There are a lot of services you can prevent from starting up that are set to do so by default with any regular WinXP installation.
A lot of them are unnessesary.
Take care in closing them though, and follow a good guide of what you can and can't disable.
this is my favourite site for XP settings:
http://www.tweakxp.com/SearchResults...&Submit=Search
There's usually some services that there are a lot of, like 'svchost' which is a generic service name that does any number of things.
A lot of them are there from your PC manufacturer to bring you 'cool' features, but really are seldom used and bog it down. Laptops are famous for these.
Others like 'QTTask' just sit there looking for new updates or waiting to run applications a millisecond faster. Do you seriously need to have a program waiting to startup Quicktime 24/7?
OSA is the office startup accelerator. You don't need it.
As an aside, if you simply MUST have different desktops, Microsoft took a page out of the Solaris/*nix pages and released a Powertool that will allow you to set up 4 different desktops.
great for switching from the porn site to a work spreadsheet desktop!!
go to the microsoft homepage and use their search for 'Powertools'.
Some other tasty ones too like 'Image Resizer' that lets you select a bunch of images and rightclick and select a new option to resize them all. Very fast.