Program usage

Hi

I would like to know how I can find out what programs are used most often on our desktops.

I seem to remember that in Win98 there was a file named optlog.log/txt which listed applications and the number of times they were used. This optlog file was used by Windows Defragmenter to prioritise which programs should be placed at the ‘front’ of the disk so they could be accessed quickly.

Does anyone know if there is a similar file available in WinXP or W2K?