Immaculens...coupola things to try...first, get stopwatch...you want to time from machine power on to when you can launch Task manager by right click on Taskbar and select.
Once you have this time, shutdown completely and restart in Safe Mode with Networking...This will give you the minimum start up time for your system.
If there is a great difference in the start times, look for multiple security programs running...you should only run 1 av, 1 as and 1 fw. A program like Norton AV (home version) is notorious for slowing the computer down all my itself...if you have this and another av program running, slow as molasses...
Create a new user. This removes issues with a damage user profile...not an uncommon problem in xp. Log in as the nedw user and time the start.
From the desktop, START, RUN and type in "msconfig" (without the quotes). Go to the Start up tab and uncheck items that are loading on start up. All tray items are unnecessary. Any item uncheck can be rechecked later.
A crowed desktop can greatly increase the load time if the graphic memory is limited. Icons in folders take less time to load. Only keep the icons you need with 1 click on your desktop.
Make sure you turn off all indexing!!! This is a great time waster.
Change your browser...the Last versions Of IE are slow. Try Firefox. Your connection to the net is what determines page loading, not your computer hardware, in general. If you have 2+ghz cpu, decent video ram, you should not see a great difference in page loading compared to your later store bought machines.
Another time killer is searching for wireless connections.
Microsoft said that you should boot xp in 45 seconds if all is right. I'd settle for 1min45...3min???? Everything you do with time slows the process down. You accumulate more errors with time.
Good luck, Paul