Have you ever had trouble sending a large email attachment? If you try to send an attachment that is too big then you may find that it bounces back to you (ie you receive a message saying that the message could not be delivered). The limiting factor may be in the recipient’s email system or in a system that the email (with attachment) has passed through on the way to the recipient.

You are not likely to encounter this problem if you are just sending average-sized spreadsheets, word processing documents or pdf files, but “media files” such as video clips, sound files, and many high-resolution picture files can very easily be far too big to send as attachments.

Large AttachmentsHow do I know the size of an attachment? This depends on the email system you are using. In Hotmail, for example, after you have added the attachment to the email you can hover your mouse over the attachment and a small box will pop up that includes the file size (eg 273kb). With most other systems the size of the attachment is shown in brackets after the name of the attachment.

What is the maximum size of an attachment? Hotmail is supposed to be able to receive 10mb attachments, Yahoo and Gmail have a limit of 25mb. These are all webmail systems. If you are using POP-based email (eg you check your email using Outlook or Windows Live Mail) then there is probably a limit set by the email servers you are using. If you have your own domain name then you are probably using your domain host’s email servers. Otherwise, you will be using your ISP’s servers. The limit they impose can be as low as 5mb. Also, the theoretical limit of a Gmail attachment is 25mb but the actual file sent through cyberspace is larger than your original file by up to about 20% so Gmail’s actual maximum is probably nearer to 20mb. Anyway, even if you know the limits of your own system, that doesn’t help in telling you what your correspondent can receive as that depends on their system rather than yours. Personally, I would not assume that an attachment of over 5mb is going to go through without trouble. I always check with the recipient that they have received anything I have sent bigger than 5mb. Note: there are 1024kb in 1mb, so if your attachment size is expressed in kb rather than mb then anything less than about 5000kb is less than 5mb and will probably be delivered without problem.

What can I do if my attachment is too big? There are several options:

  • split the file up into smaller pieces. There is software available for splitting and rejoining files. I don’t recommend this method.
  • compress the file into a (smaller) zip file. This can work very well for some file types (eg tif files) but not have very much effect on others (eg jpg picture files, that are already optimised for the trade-off between size and quality). Zip files are a good idea, by the way, if you are sending many attachments as they can all be sent in one zip file for unpacking at the recipient’s end.
  • use an online service such as www.goaruna.com

Using GoAruna, you don’t even have to register if you just wish to send a single file. All you need to do is enter your own and the recipient’s email addresses and upload the file you wish to attach. The recipient is then sent an email with a link so that they can download the file. Although there is a time limit (seven days) on the availability of the download, this method does have the advantage that the download is under the control of the recipient. This can be better than having their email system tied up while a large attachment download takes place (although this is becoming less important as internet connections become faster). A single file sent this way by GoAruna can be up to 100mb. By registering with Aruna, you can also have 2gb of online storage. This can be used for backups and/or making files available to other people that may otherwise have needed to be sent as email attachments. Note: just as there are 1024kb in 1mb, there are 1024mb in 1gb.

There are other services similar to GoAruna. You may like to look at these:


Groan. Computer passwords are a nuisance. Among my own clients, the typical reaction when the subject comes up is along the lines of “they’re just a nuisance. I use the same one for everything so that I can remember it” or “I put the password in once and asked the system to remember it and now I have no idea what the password is“.

If you start researching, you will find that the advice on passwords includes things like:

  • make the password at least 20 characters long and include upper case, lower case, numbers, punctuation marks – as if!
  • change your passwords every month (or week) – as if!
  • don’t use passwords that are the names of loved one (including cats’ names).
  • keep your passwords secret.

Username and password entryWell, pretty well all my clients breach all those recommendations and, I must admit, so do I (but I’d never have a cat, so that bit’s ok).

So, my recommendation is that we should be practical. We are going to have to live with passwords for the foreseeable future, so I have developed a simple strategy for myself that I hope may be of use to others. I aim for a workable compromise between security and practicality. The elements of my own strategy are as follows:

1) As soon as I create or receive a new password that I don’t want to lose I record it in my encrypted and password-protected database. This database is regularly backed up and archived. Copies are stored off-site (ie not in my home).

It has taken me years to learn this simple lesson and make sure that I stick to it. How many times have you written a password down on a tatty piece of paper, assuming that you will be able to magically find said scrap of paper in three years time when you’re in a flap because your router has just locked you out of your wireless connection? The alternative bad approach is to allocate a password that you “are bound to remember” so you don’t need to write it down. Yea, right! Seen that one dozens of times. Something that seems utterly unforgettable today is probably going to be either utterly forgotten in a month or simple to guess by a baddie (who has now probably also got access to everything else of yours that is password-protected.)

Let’s be practical and mercenary about this so that maybe you can appreciate the importance. Suppose that, as a client, you call me in because the wireless networking part of Windows has suddenly forgotten your password (also known as a “network key” or “passkey”). Depending on where you are, my minimum visit charge will be £80-£110. OK, so there’s time in the minimum visit length (1.5-2hrs) to do other jobs that need doing as well, but if I need to get into the router’s settings and re-allocate a password, that could take anywhere from 5 minutes to 1 hour. So, it’s cost from £5 to £55 to re-establish a wireless connection – just because you didn’t know the passkey. To me, that sounds like a hefty bill (or fine!) for not being rigorous in recording the password safely where it can be found without fail and without delay.

2) If the password relates to something I really don’t care about (such as a registration I had to make on a website just to get what I wanted from that site) then I am quite happy to use the same short, memorable, password for all such occasions (yes, a cat’s name if you must). For the sake of the convenience of not engaging my brain, I am prepared to take the risks associated with this strategy.

3) If the password relates to something a bit more important then I try to create a password that consists of something about that site or purpose that I will remember plus something else that fits the criteria of being both very memorable to me and completely unguessable by anyone else. Examples might be “opendoor:waterstones” or “opendoor:sainsbury”.

4) If the password is mega-important and not easily defined using (3) above, then I use or create a password consisting of 2 or 3 elements that are very personal to me, that are not dictionary words, that include punctuation marks and numbers, and that relate to things that are way in the past and will not turn up on any internet search. I’m not going into detail because I’m not writing a handbook for hackers getting into my systems, but some examples of these “elements” could be:

  • names or nicknames of memorable teachers, friends, girlfriends – all well in the past
  • postcodes or street names that have had significance in the past (but are not connected to me now)
  • registration numbers of vehicles owned long ago
  • old telephone numbers
  • favourite music or musicians from long ago

As a general rule, I do not use anything that is likely to have been entered into a computer in connection with me in the last, say, 20 years.

Just a couple more points. I’m not going into cryptography here and I don’t want to stray across the boundary of paranoia, but let’s remember that someone may try to crack a password by guesswork as they know something about you (your cat again!) or they may try by brute force. This means using a computer to try every combination until one works. The only point I wish to make here is that computing power is increasing so fast that we need longer and longer passwords in order to make “brute force attacks” unlikely to succeed. I’ve seen recommendations that every password should be 50 characters long! That is, of course, completely impractical. However, I am making myself a rule now that my important passwords are at least 14 characters long. Don’t ask me how I arrived at that figure, but if you’re interested in the strength of your passwords have a look at these sites:


And finally – Permissible Characters. One thing that makes creating and remembering passwords even more difficult is that some registration processes allow you to use non-alphabetic characters, some forbid it, and some insist on it. Accepting the compromise between security and practicality, my own method for negotiating this is to start by trying to include specific non-alphabetic characters that I will remember and then taking them out if they are dis-allowed. I use the same approach for including/excluding numbers and including/excluding mixes of case (ie using a mixture of capital letters and normal, lower-case letters). That way, I probably only have two or three possible combinations to try when I enter the password. And if I don’t get it in two or three attempts, I consult the database mentioned in (1) above and smugly congratulate myself for being so organised (at last).

Cloud Computing has become a buzz-word recently, but what is it? Cloud computing is internet-based computing. It is the provision of computing services over the internet that would previously have been provided locally on one’s own computer.

Example of traditional computing

Most people have a word processing package. This is a program that is installed on their own computer. If you have such a program then you can start it running, create a document, save it or print, close the program and all of this is done without any internet connection. You may have originally acquired the program by downloading it from the internet, but it is now installed on your own computer and you can use it without an internet connection. Quite possibly, you do this with Microsoft Word.

Example of Cloud computing

Suppose you don’t have a word processing program on your computer but you have an internet connection and you have Internet Explorer or Firefox or another web browser (a web browser is a program that allows you to see – and interact with – web sites). You can create, save, and print your document using a service such as Google Docs. The word processor is provided by Google via your web browser. All the programming for the word processor is at “their end”, but you can still create your document etc. This is Cloud Computing.

A slightly different way of looking at this is that instead of buying a product (a word processing package that you install on your own computer and then use whenever you want at no further cost) you are instead buying a service (the provision of word processing facilities). Cloud computing services are often provided on a basis of paying for what you use – in terms of time, or amount of data stored for instance. There are also free cloud computing services (see below).

Why is it called “Cloud Computing”?Cloud computing

In computer flowcharts and diagrams, it has become the convention to picture any part of the process that happens via the internet as happening in a cloud – see diagram

Pros of Cloud Computing

  • For organisations (with several or many users) cloud computing can be more flexible and quicker (and, therefore, cheaper) to deploy. The larger the organisation, the more this is likely to apply.
  • Cashflow for the user is improved as services are paid for as they are used, rather than up-front. Cashflow is also helped as expenditure is moved from capital to revenue expenditure (completely claimable against tax in the current period rather than written off over a number of years).
  • Updates, bug fixes and so on are very easy and inexpensive for the supplier to provide as there are no downloads or CDs/DVDs to supply, and the timing is under their control.
  • The user can access the program/service from any suitable computer with internet access.
  • Users don’t have to download and install updates, bug fixes etc.
  • Cloud computing tends to mean that users can use smaller, less-powerful (and, therefore, less expensive) computers to access the programs.

Cons of Cloud Computing

  • There is a perceived loss of control as data may be stored in the cloud and program functionality may change without the user wanting it or needing it to change.
  • It can be slower to access and use as the “conversation” between user and program has to happen over the internet rather than just on the the local computer.
  • Cloud programs tend to be less sophisticated in their power, options and configurability.
  • There are huge problems if internet access goes down or if the service provider’s system goes down.
  • There are security implications as data is constantly passed across the internet and may be stored remotely.

Some examples of cloud computing resources that are free of charge can be found here:

http://www.docs.google.com/ – word processing, spreadsheet, and drawing
http://office.microsoft.com/en-us/web-apps/ – Word, Excel, PowerPoint, OneNote
http://mail.google.com/mail/ – Gmail webmail

Notice the rather ominous “1” in the title. This is a subject that will take more than one blog post. So, today let’s just think about what “backups” mean and what they don’t mean.

When I asked Google to define “backup” the first offering was

an accumulation caused by clogging or a stoppage; “a traffic backup on the main street”; “he discovered a backup in the toilet”

You’ll be pleased to learn that that’s not what we mean here. A better definition (offered by Wikipaedia) …

In information technology, a backup or the process of backing up refers to making copies of data so that these additional copies may be used to restore the original after a data loss event. These additional copies are typically called “backups. …”

3.5 inch External Drive

3.5 inch External Drive

So at its simplest, a backup is a copy that can be used to replace an original if it is lost, deleted, damaged. This backup can be a copy of a single file (eg an important spreadsheet) or many files. At its simplest, a backup can reside on the same drive as the original. The problem is that if the entire drive fails then the backup is also lost. Having a backup on an external drive is a much better idea but that still wouldn’t avail you if all your computer stuff was stolen or in the event of flood or fire. The only way to be really sure that the backup will be there if you need it is to keep a backup in a location physically separated from the original. In practice, I’ve only ever very rarely managed to train my clients to such a degree!
What a Backup Isn’t

A backup is not usually a copy of any of the myriad files that make up the Windows (or Mac) operating system, nor a copy of the files that make up the programs on your computer (eg Microsoft Office, Photoshop). If we suspect that something has gone wrong with Windows or with a program file then the best thing to do usually is to un-install the program and re-install it. In other words, we don’t just copy back files that are in a backup, but set in motion the process of removing the program completely in the proper way and then putting it back from scratch from the original master CD/DVD or downloaded file. The reason for this is that program files have to be copied and set up so that they work in the specific situation and in concert with the other programs and operating system. Copying files is not enough to achieve this so we don’t back up program files.

What Data should be backed up?

Your own stuff. The documents and spreadsheets and pictures and videos and all the other stuff that is YOURS and that you would not want to lose.

There are also other types of file that are not quite so easily imaginable as data but which you wouldn’t want to lose – eg that huge list of bookmarks (also known as favorites (sic)) that you build up in your web browser (Internet Explorer, Firefox, Chrome, Safari, Opera or whichever browser you use). That list of websites is nothing more than that – a list – but I’ve seen a lot of clients looking very deflated when they realise they’ve lost it.

2.5 inch External Drive

2.5 inch External Drive

A hugely important part of backup data can be your email data. This is the email messages themselves, but can also be your contact information. If you only send, view, and receive your data through a web browser then your email data is not being stored on your own computer but on the computers of the service providers. This covers services such as Hotmail, Gmail, AOL mail, Yahoo, and others. This is known as webmail.


If, however, you access your email through a program on your computer (such as Windows Live Mail, Outlook, Outlook Express) then your email data is stored on your own computer. Your email provider may have a copy of your recent email history on their own computers (also known as mail servers) but it could be as little as the last seven days worth of data. Don’t rely on your mail servers as email data backups.

It’s also true that webmail can usually be accessed and downloaded with programs such as Outlook (as in the paragraph above), but we don’t need to split hairs about that now.

Having established an idea of what it is that we want to back up, let’s just finish this definition of what a backup is by considering some similar ideas:

An archive – in computer terms, an archive is just a backup but with one important difference. It is never over-written. Suppose you back up your data to an external hard drive. That drive is going to get full and you may wish to delete older backups to make room for newer ones. That means that you can’t always rely on your backups to tell you exactly what your accounts data (for instance) looked like on 23rd April 2009 (for instance). So, we often create archives in the knowledge that whatever happens we can see the data as it looked at a particular time in the past. Archives can be created in exactly the same way as a backup or by a different method. Often, for instance, archives are created on CDs or DVDs, whereas backups are made on external hard drives or USB pen drives (also known as thumb drives or memory sticks. A Memory Stick is actually a proprietary Sony device, so it is a misnomer to describe a generic USB pen drive as such).


An image – when we’re talking about backups an image is not a photograph. It’s a different meaning of the word and what it means is a complete, thorough, 100%, copy of EVERYTHING that is on your hard drive (or a sub-division of a hard drive such as a partition). An image can only be created using special software but it does seem to contradict what I said earlier about not being able to back up programs because a complete total image of your drive can actually be used to restore your computer to exactly what it looked like at the time the image was made – operating system, programs, data, the whole lot. But it’s not the panacea it sounds like because restoring an image could result in losing all the changes to the data that happened after the image was created.

Pen Drive

Pen Drive

A clone – similar to an image, a clone is the entire copying of one drive (or partition) to another similar drive so that it can be swapped with the original in case of disaster. The problem with images and clones is that they can take a while to create, you can only be completely certain they’ve worked by installing them, and they don’t change as data is added or changed.


That’s an introduction to backups. The next blog on this subject will look at the actual creating of backups in more detail.

One final word: I implore you to keep your master program discs all in one place and know where that place is. I would include in that any data backups and archives on “loose” media such as CDs or DVDs. So many times in the past I have been summoned by a distraught client with an apparent disaster on their hands who needs programs (and maybe data) to be re-installed but they can’t find their discs. This is already a fraught situation. It just makes it more stressful and more expensive if the client can’t find the discs. This doesn’t need to get complicated: just put everything in the same box and know where that box is.

© 2011-2019 David Leonard
Computer Support in London
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