Ah, services. Useful little things - but only when they're needed. If your system is running services that it doesn't need, then it's wasting memory. XP Pro users can control their services by going to Start } Run and typing "services.msc" and hitting enter. Behold the mighty service manager! Rather than go through all the possible services myself, I'll link to this site:
Black Viper has done an awesome job of listing just about every service you're ever likely to come across (updated for SP2, as well), and also hosts registry files for simple, "all-in-one" tweakage. There's also some good information for XP Home users wishing to change their services as well.
NB: If you decide to disable the "Automatic Update" service, you may have issues using Windows Update on the Microsoft site as of Service Pack 2. If you plan to be updating regularly, consider leaving the "Automatic Update" service as "Automatic".
This tweak is valid for XP Pro, but with any (or no) Service Pack installed. By default, XP tracks each individual's file access patterns - which documents they access, when and how often, and then customizes some Windows features around this data. An example of this is the "personalized" default start menu. If, like me, you use the classic start menu, or just want to speed your box up a little by reducing the system overhead, you can disable user tracking by going to Start } Run and typing "gpedit.msc".
Anyone who has made the unfortunate move of buying an USB modem will know how many CPU cycles those things crunch. The same goes for most USB devices - and, by extension, the mere act of searching for any attached USB devices. By default, XP searches for newly connected USB devices every 1ms. You can change this to every 5ms (provided you can wait the extra 4ms) by altering (or adding) the following registry value.
and then create a REG_SZ key called "IdleEnable" before setting its value to "1". You'll get a minor (perhaps not easily noticeable) improvement - but an improvement all the same!
Processor Power +
This tweak, like the couple above, can be performed in XP before or after Service Pack installation. There are a set of various functions that XP performs approximately once every three days, and then only when the system is idle. These functions could include disk defragmentation-like processes, file sorting, et cetera. As actually executing these programs may take some time (between 10 and 15 minutes), don't use this tweak and expect immediate results.
To force XP to complete any queued tasks, open Start } Run and type:
before pressing "Enter". Your hard drive light should flash with activity while the task are being carried out, or you can examine the services running by opening the Task Manager (Ctrl + Alt + Delete).
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