Many of us have whined and bitched about Windows XP slowness. Why do gigahertz CPU's behave so sluggishly?
Answer, the CPU is running all sorts of invisible programs behind your back. A lot of these busy little CPU hogs do nothing useful, they just slow down your machine. You can see these little ramhogs in Task Manager. Just hit Control-Alt-Delete once and Task Manager will pop up. Click on the Process tab and obtain a list of all the hidden programs. My machine runs well with no more than 21 processes. I have seen machines burdened with as many as 50.
If you are in the quest for speed under Windows, the first step is to remove all the programs you don't use. Click on Start -> Settings -> Control Panel and select the "Add or remove programs" icon. This gives you a list off all programs installed on the machine. Keep the ones you use, or think you might use sometime. Keep the Windows service packs, Internet Explorer, Java, Microsoft .net and anything that the name suggests is a hardware driver. Blow away everything else, the cheezy games you never play, the freeby programs that you never used. This stuff mostly came with the machine and is obsolete by now. If you should really need one later, you can find new and up to date versions on the net.
Blowing away the excess stuff frees up disk space, and sometimes kills off run-behind-your-back programs. Sometimes it kills off virii that have been hiding in the clutter of files. Blowing away programs is SUPPOSED to remove all disk files, all drivers, all registry patches and scrub the program clean off your machine. Not all programs remove cleanly. You can do some clean up after the sloppy programs by blowing away any remaining files with Windows Explorer. Take notes on what programs you removed as aide to finding their files on disk.
After you zap all the useless programs, you can trim some fat off Windows.
From inside the "Add and Remove Programs" applet, click on "Add/ Remove Windows Components. My machine runs fine with nothing more than Windows Explorer and Networking Services. Be sure to uncheck Indexing Services, its a useless CPU hog. I would dump OutLook Express and use Thunderbird to do email. For that matter the only reason I keep Internet Explorer around is to make Windows Update work. I use Firefox for all my web browsing.
When done, count the number of processes in Task Manager. Depending, you might have killed off a few CPU hogs.