A computer don't need to "warm up".
It looks like your boot process is taking an excessive time.
Once you have Windows up and running, you probably need to do some maintenance:
Check your notification area. Disable any preloaders and quick starters. They are useless and make the computer much slower to start. Disable any item that you don't use or realy need. Not counting the volume and network icons, most peoples should have about 10 or less icons in that area.
Clean up your temporary files, old prefetch data, obsolete files, Windows update uninstallers, and uninstall applications that you no longer use or need. This could give you back several gigabites of disk space.
For the cleanup, I suggest using CCleaner from Pyriform. It's a great and free cleaner utility. It's safe to use. It can also be used to do registry maintenance by finding and removing obsolete entries.
Next, from the controll pannel, open the add and remove programms applet.
Go trough the list of installed programms. If you see any that you no longer use, uninstall them. Don't touch any that looks like they are drivers related, like any from nVidia, ATI or AMD...
Once you uninstalled un-needed programms and applications, run CCleaner a second time.
Disk clutter makes the computer work hard to find any needed files.
!!! VERY, VERY IMPORTANT !!!
Defragment your drive.
The defragmenter included with Windows XP is NOT good enough. You can get Defraggler, also from Pyriform and free. It can defragment a drive that the included defragmenter is unable to optimise, like if you have less than about 20% free space...
Start the defragmentation. Be patient, if you never defragmented your drive before, it can easily take several hours to complete. (the previous step of cleaning clutter makes the defragmentation much faster)
Once the defragmentation is finished, set the defragmenter on a scedule, weekly is a good period, to maintain your drive in an unfragmented state.
Fragmentation is a HUGE performance KILLER! When files are broken up in many small fragments, you waste a lot of time reading them and even more writing to them.
Install some good anti-virus. 3 good free ones are: AVG, Aira and Avast. There is also a very decent offering from Microsoft, also avaylable for free.
Those are at least as good as many paid ones.
Let it do the first scan and correct any problem found.
Install Spybot and do a manual scan. It's available for free and can find and remove many performance sapping non-viral pests.
Another thing that can help in the long run:
Install a second hard drive and place your personnal data on it. The goal is to physicaly separate the operating system and applications from the data.
That way, if you need to reinstall WIndows, your files will be completely safe. Also, the accumulation of files will not affect the performance of Windows.
With a second drive, you should move the swap file to that drive (it usualy gives you a performance boost). It's also a good idea to also redirect the temporary folders to that drive.
Electro, January 2013
