Computer running very slowly

[DazzerT]

I presume my XP computer is running very slowly because according to msconfig there are loads of apps running at startup and under services.
There are loads of Microsoft ones as well as unknown ones. But how do I know which ones I can disable?
Dazzer

[shadowpr]

For services: http://www.blackviper.com/WinXP/servicecfg.htm

For startup programs, just uncheck anything that you know you don't need starting up automatically. The rest is probably safe to uncheck, but you could just list them here and we can double check for you.

[glc]

You can essentially disable anything you want. Worst case, you would need to boot it into safe mode to re-enable something you shouldn't have disabled, or do a system restore - just make a restore point before you start playing.