Start -> Run -> msconfig
On the services tab:
Anything that's unnecessary, set to manual and stop.
On the startup tab:
Uncheck anything that's unnecessary.
Basically, stop all the services and programs that aren't system-related from getting fired up when your user account logs in. See if this improves performance. If it doesn't, you know we're dealing with another issue.
Also, launch task manager before you open IE and look at memory and CPU usage while the computer lags.
Remember, Windows is a pretty expensive tool in terms of processor and memory usage. On older machines, booting just normally takes a long time. The best you can do is minimize the number of things it loads along with the operating system to cut down on that.
http://www.pchell.com/hardware/mastersl ... lect.shtml
changing your IDE HD role select jumpers can apparently reduce windows load time by up to 2 minutes.
Reduce the Number of Fonts installed
c:\windows\fonts
pull all the ones you think are unnecessary out to a backup folder and see how this affects boot time.
All this taken from a simple google search. come on now!