Windows XP pro start up / re-install problems

[palomino]

I have a 4 year old desktop PC, 2.4 Mhz P 4 which came loaded with XP pro SP 1.
Subsequently I had upgraded the OS to XP SP 2 via the Microsoft update site which I use regularly. After returning from a 10 day vacatiopn I found thaI had forgotten to turn the PC off before leaving and that it was still on when I got back. However as the monitor screen was black I presumed it had gone into stand by mode. I was unable to get it out of the stand by mode so I switched it off and on powering the PC up again, found that the PC just would not boot up.
Since I had not bothered to make an automatic recovery CD / diskette, I managed to find the old XP Pro SP1 CD and got the PC to boot up.
After which I found that Office 2003 programs worked ok and all my data files were intact but had to re-install most of the other non MS applications and Windows Media player and other audi programs did not work. Most of these returned the Application Launcher message " failed to upload configuration".
Downloaded XP SP 2 from the MS update site bit on restarting, find that the PC just refuses to boot up from the hard drive (or from the old XP SP 1 CD). I get error messages about a problem with the nv4_disp file and the PC getting stuck in an "infinite loop" and also "C Media AC 97 audi device not passing the Windows logo test" and there being compatibility problems with this driver and Win XP. I do not have much knowledge about installing / working with OS problems and would appreciate help in getting this sorted without deleting / over writing my data files.
Thanks

[Midknyte]

don't worry about the cmedia not being WHQL. just accept them.

you need to download updated video drivers if you have nv4_disp errors. boot to safe mode to load the new drivers.

you need to make a slipstreamed disc already. SP2 is 3 years old. if you mean that you did a repair install, you are supposed to do the repair with a disc of the same SP level for best results.
http://www.simplyguides.net/guides/u...ostreamer.html

[BipolarBill]

Also, check for bad capacitors:

www.badcaps.net