[AndyB]

Try to always keep a backup of your files on an external portable, or if they are smaller files, a flash drive.

Make sure you have AdAware SE as well as CCleaner and that you run both frequently.

Don't crowd your desktop with icons, it only decreases productivity. For files, simply stick them in folders within your My Documents and for programs, if you use them a lot, put them in your quick launch section on your startbar.

If your computer is running slow, don't put up with it, run AdAware, CCleaner, and run a virus scan using a reliable security program (I recommend AVG).

As far as hardware goes, try and open up your computer once every couple of months and clean out all the fans and vents with a can of compressed air.