Hers some groovy info for those that HAVE installed it. Please note if you are running a hack copy of XP you will need to change your serial key which can be done via some online guides as MICROSOFT have put something into SP2 to detect it
My copy runs pretty sweetly and only seems to conflict with two programs of whihc each will be releasing a patch
This will take you about 5 minutes and will make your computer faster, more stable and also more secure. I've switched off all the services mentioned below apart from the Task Scheduler and my computer runs much better! And so it should, there was a fuckload of software (services) that I didn't need running ALL THE TIME!
On to the guide...
The code-bloat problem seems to get worse with every release of Windows—each new release seems to run slower than the preceding one. In most cases, the problem doesn't stem from the base OS code but from the fact that each new release tends to incorporate more functionality. One key area that continues to expand is services: Windows XP automatically starts 36 services. Very few users need all those services, however, and by trimming back unused services, you can make your system run more efficiently.
To get to the Services menu, go to the Control Panel, then Administrative Tools and then Services. Next double-click the service you wish to modify to open its Properties sheet. On the General tab, click the Startup type drop-down box and select Disabled. If you decide to re-enable a service later on, simply change Startup type back to either Automatic or Manual. Here is a list of XP services that you can consider turning off..
"Alerter" - Disable
The Alerter service notifies users of administrative alerts on a network. Most home users aren't on a workstation that is part of an administered network, so this service usually is not required.
"ClipBook" - Disable
Used to store information (cut / paste) and share it with other computers. I have never found enough need for this to allow this service to always be running. Why would I want to allow other computers access to what I cut and paste anyway? Disable it.
"Computer Browser" - Disable
Computer Browser service maintains a listing of computers and resources located on the network. This service is not required on a standalone system. In fact, even if you want to browse the network (workgroup or domain) or have mapped network shares as local hard drives, you can still do so. On a large network, one computer is designated the "master" browser and another one is the "backup" browser. All others just announce they are available every 12 minutes to "take over" duties if one of the other computers fail. No lag time is discernable if this service remains disabled on all but one computer. Honestly, I do not even believe one needs to be running.
"Error Reporting" - Disable
The Error Reporting service contacts Microsoft / Big Brother when applications encounter an error. I personally do not like this. I feel it is a waste of memory and resources. On the other hand, if you are experiencing system crashes often, the best way to deal with them may be to report them using this tool.
"Help and Support" - Disable
This service is required for Microsoft's online (or offline) help documents. If you ever "attempt" to use Help and Support, the service places itself back into "Automatic" and starts even if you already had this service set to disabled! I try to avoid as much Microsoft help as I can...
"Indexing Service" - Disable
This service always has been a major resource hog. I NEVER recommend having this service enabled. Remove the function via the "Add / Remove Programs" icon in the control panel (Add/Remove Windows Components). It uses about 500 K to 2 MB in an idle state, not to mention the amount of memory and CPU resources it takes to INDEX the drives. I have had people (and witnessed it on other people's computers) report to me that the Indexing Service sometimes starts up EVEN while the system is NOT idle... like in the middle of a game! You may feel, as I do, that this is unacceptable. If your computer suddenly seems "sluggish" when searching for files, Indexing Service could be the cause of it so try switching it back on.
"Infrared Monitor" - Disable
Unless you're on a laptop with an Infrared port then there is no benefit in having this service constantly listening for Infrared connections, in fact, all it does is waste system resources (only a little though). If you're on a laptop or an Infrared equipped PC, leave this on. Everyone else should disable it.
"IPSEC Services" - Disable
May be required on some domains or VPN connections, but the "average" user will not need this.
"Net Logon" - Disable
Used for logging onto a Domain Controller. This service is not required on a standalone system, or for a "home" network.
"NetMeeting Remote Desktop Sharing" - Disable
Enables a user to access your computer using NetMeeting. This may create a BIG open door for the unwanted. If you are worried about security, disable this function. Even if you were not worried, I would still get rid of it.
"Network DDE" - Disable
I have not found a good use for this service. It uses about 1.5 MB memory when idle. Unless you use the remote ClipBook service, disable it.
"Network DDE DSDM" - Disable
I have not found a good use for this service, other than consuming system resources

Unless you use remote ClipBook, disable it.
"Performance Logs and Alerts" - Disable
Collect performance data on a schedule and send the information to a log or trigger an alert. This may be a super geek tool, but I feel that the overhead associated with it is not worth the benefit. If you don't create or check performance logs then disable this service.
"Portable Media Serial Number" - Disable
Retrieves serial numbers from portable music players connected to your computer. I have not really found a good reason to keep this service always running. I am not aware of anything that actually requires it. Disable it unless something of yours ceases to function properly, such as Windows Media Player with Microsoft's integration with "Digital Rights Management" and copy protection.
"Remote Desktop Help Session Manager" - Disable
Manages and controls Remote Assistance. If you do not want or need to use this feature, disable it. In an idle state, this service sucks up 3.4 MB to 4 MB of RAM.
"Remote Registry" - Disable
The Remote Registry service lets you access and manipulate the registry on other networked systems. This service can be useful on administrative workstations, but it can also be a potentially serious security exposure on end users' network clients. I strongly recommend disabling the Remote Registry service on most client systems.
"Routing and Remote Access" - Disable
Allows computers to dial in to the local computer through a modem (or other devices) to access the local network using a standard or VPN connection. Unless you require this functionality, disable it for security reasons.
"Secondary Logon" - Disable
Enables starting processes under alternate credentials. I have never found a reason to keep this service running. I have always considered "Alternate Credentials" someone other than me! Not my idea of fun... Really, though, it allows a "limited user" account to start an application or process with higher privileges, such as the Administrator account or another user. You can also have a privileged user start an application or process with limited privileged account. If you right-click a file, the menu will display "Run As" option. If you disable this service, that function will no longer be available, but chances are you'll never need it anyway.
"Server" - Disable
The Server service provides remote procedure call (RPC) support as well as support for file and print serving. Although this service is necessary on server systems, it can pose a security risk on network clients that don't need to provide file and print serving.
"Smart Card" - Disable
Supports the use of a Smart Card for local or network computer authentication. If you do not have a "Smart Card," or you do not know what a Smart Card is, you do not need this service running. Save the 1.1 MB to 1.4 MB of RAM this service uses.
"SSDP Discovery Service" - Disable
Used to locate UPnP devices on your home network. Used in conjunction with Universal Plug and Play Device Host, it detects and configures UPnP devices on your home network. For security reasons and for the fact that I doubt that you have any of these devices, disable this service. If any EXTERNAL network device does not function because of this service being disabled, place it back in to automatic.
"Task Scheduler" - You decide if you need this or not
The Task Scheduler lets your system automatically run programs and scripts at a prescheduled time. Some third-party virus scanners and backup utilities use this service; others install their own scheduling service. To see whether anything on your system uses this service, open the Scheduled Tasks folder in Control Panel. If the folder is empty, you can most probably disable Task Scheduler without sacrificing functionality.
"TCP/IP NetBIOS Helper" - Disable
If you're still running WINS and NetBIOS on your network, you'll want the TCP/IP NetBios Helper service to remain enabled. However, if your network does not use NetBIOS and / or WINS (which yours doesn't), disable this function.
"Telnet" - Disable
This service is not available on Windows XP Home. It allows remote login to the local computer via the telnet function. For security reasons, disable this unless you specifically require its functionality. You will save about 2 MB of RAM by plugging this security hole.
"Uninterruptible Power Supply" - Disable
If you don't have a UPS connected to your serial port, you should disable this service.
"Wireless Zero Configuration" - Disable
As its name suggests, the Wireless Zero Configuration service supports automatic configuration of 802.11 wireless connections. Mobile users of laptops and tablet PCs should probably leave this service active, but networked client systems usually have no need for wireless connections and can safely disable the service and reclaim some system resources.