I have a Compaq desktop computer which I don't use very often. It used to be my main machine but I now mainly use it to back up data or the scanner which is attached to it.

It has been running infuriatingly slowly recently so I decided to reinstall Windows, using the 'System Recovery' option which replaces the contents of the hard drive with the 'factory fresh' copy of XP.

The computer now runs quite quickly again. Boot-up time has been reduced from over 4 minutes to 38 seconds. The computer had so much software installed, and a lot of rubbish would load on start-up. The desktop actually used to appear after 2½ minutes but it was a further 2 minutes before you could open any windows or run any programs.

Clicking on files and opening windows is amazingly quick now. There used to be several seconds of disk-thrashing and a long wait when the "Start" button was clicked. Now the menu appears pretty much instantly. I had started to wonder whether my old computer had always been this slow, and I only thought I remembered it being fast when new, but no. It is back to being quick and responsive again.