some people have trimmed XP's startup, so it only takes 20 seconds. no kidding!
Here are three examples of services in XP that you may not need turned on all the time:
Automatic Updates
Used to see if there are any updates available for download. I choose to manually update due to the very long lag time from when an update is available to when WinXP reports it. If you decide to disable this service, it's very important that you check the Windows Update site often to ensure the latest patches are installed. Take note: Manual (and Automatic) update via the Windows Update website requires that a component called Cryptographic Services is running. Place this service in automatic mode if you do not wish to update manually.
Help and Support
Required for Microsoft's online help documents. If you ever use Help and Support, this service will be placed back in automatic mode even if you've already disabled this service. I would avoid as much "Microsoft help" as I can.
Messenger
Sends messages between clients and servers. Not needed under normal conditions at your home. This has nothing to do with MSN Messenger, nor is it WinPopUp.
For more information on Windows XP services and how you can deactivate and activate them, visit this website:
BlkViper.com