So if you are running a business based around a computer a regular backup of your data files is an absolute must. In my experience as a computer consultant many times data has been lost because of a burglary. If your house or office is burgled invariably theives take computers. They are easily carried and readily sold.

And this raises question of what should you backup? Well that's a hard question to answer because everyone's computer is different so I'll explain what I backup on my computer. My computer runs Microsoft Windows operating system and has a single 'C:' disk drive.

I have all of my data stored in directories as follows: C:WebSItes (the source of all my web sites, including text, graphics and scripts). C:Work which is where I keep all correspondence and general junk C:Courses where all text to my courses is held C:My Download Files where all original files of software that I download are stored.

The other directory I copy is C:Documents and Settings which is where email files are stored. Without my email I'd be out of business!

My backup system is simple, a CD writer, some blank CDs and Nero Burning software (came free with CD writer).

And once I've taken my backup I take CDs to a friend's house for safe keeping. I do this every week.

If you downloaded software then you at least need URL where you purchased software from.

If you have a record of software's acquisition then you can prove to original supplier fact of your purchase and most suppliers will provide a copy (perhaps with a small handling charge). Obviously if you can't prove your purchase then bad luck you're going to have to buy it again!

As an aside, whenever possible make a backup copy of all software you purchase before you install it. Most software is readily copyable, both technically and legally. Every software license agreement I have ever seen allows software to be copied for a legitimate backup purpose. And as with any backup, it should kept at a different location than computer.

In addition, if you make any upgrades to software then full details of these should also be recorded.

Similar records should be maintained of your hardware. As a minimum, record serial numbers of all hardware items, along with cost, date and where purchased. For an insurance claim or Police report these are vital facts.

I also find it useful to keep a page devoted to my internet connection. This includes all details needed to connect such as TCP/IP address (or phone number if on dial-up), sign-in and email address and passwords, server details such as pop and smtp names and any security options you've selected. Whilst all of this information is relatively simple to setup again, without details it can be very time consuming.

Another page should be devoted to operating system. My current computer was purchased about 18 months ago and came with a copy of Windows 98. I subsequently upgraded to Windows 98 SE, then earlier last year I bought an upgrade copy of Windows XP. And so to rebuild software environment I'd need to reinstall Windows 98, perform upgrade to SE and then perform upgrade to Windows XP. Without a few notes in my diary I'd probably not remember sequence of events. Likely my new computer would have a copy of Windows with it and so this page would be unnecessary. But if you're only replacing a failed hard drive then this information is necessary.

Perhaps you think hard drives don't fail. I live in a small town with a population of 30,000 people. A good friend owns only computer shop. He advises that not a day goes by when at least one person doesn't come in with a broken hard drive.

One last thought, throughout your diary make notes of any special options or features that you install or set.