Windows XP has a lot of services, some of which are not needed for normal use. To speed up and increase your systems security, disable these services.
To enter service manager-
Go to Start > Run and type services.msc and hit enter.
Scroll down and highlight the service you want to adjust, right-click on it and choose Properties.
Now click the stop button and select Disable or Manual in the Startup Type scroll bar.
A useful tip is that instead of disabling something you are unsure of, set it to manual. When you restart your machine if that service has started then it is probably required by one of your components or software products. If it is still OFF then consider disabling it for greater protection.
More Here