I apologize in advance for the long post....

System 1 (Main system):
AMD 2700+
Asus nForce2 A7N8X 333 FSB
1.5 GB PC3200
HDD1: 80 GB Western Digital Caviar NTFS Windows XP Professional SP2 (Main drive)
HDD2: 60 GB Seagate FAT32 Windows 98

System 2 (Backup system):
AMD 1700 TBird
Soyo Dragon Ultra Platinum 333 FSB
256 MB PC133
HDD1: 40 GB Quantum Fireball NTFS Windows XP Professional SP2

This problem invloves 3 hard drives. I'll call them A, B and C.
A - 80 GB XP Pro
B - 60 GB Windows 98
C - 40 GB XP Pro

My main system uses drives A and B, booting only from drive A and using drive B as storage. Recently, I've been getting a lot of blue screen STOP errors in Windows XP Pro stemming from USBPORT.SYS. I've ALSO been getting errors when my system POSTs that say "Warning, CPU have over speed!!". It's not overclocked, but I toned down my CPU settings anyway and the errors seemed to subside, but earlier this evening I was installing a program and got another blue screen STOP error with SCSIPORT.SYS listed as the culprit. I attempted a restart, but now XP won't load at all, and on some startups I am now getting the "CPU has over speed" error again.

The system still POSTs but I noticed 2 problems. If full POST check is enabled, the system attempts to check the memory for errors at startup, however this check never ends. It just cycles through the memory over and over again until the system is restarted. It never reports any errors though... So if I turn off full POST check, the system finishes POSTing and I get the "Verifying DMI Pool Data...." message, and then it attempts to boot XP. But instead of booting XP, the system just restarts itself.

I changed the boot priority so disk B (Windows 98) would boot first, and restarted. Windows 98 booted fine... so i figure disk A is probably corrupted in some way.

I thought I'd try swapping disk A into my backup system to see if it booted up there. So, I hooked it up, booted the backup system, and low and behold I got the "Windows did not shut down properly.... Safe Mode/Last Good Config/Start Normally" message. I tried Safe Mode, and the boot log started scrolling, but then it hung. So I restarted and tried "Last Good Configuration". This time I got the grey loading bar before the Windows XP loading screen:

| | | | | | | | | | | | | | | | | | | | | | | | - looks a little something like that.

The progress bar finishes loading, but then the system hangs. So I restarted and tried "Start Windows Normally" which resulted in the same thing.

By now I'm convinced that there's something wrong with disk A, so I set it as slave on my backup system and booted with drive C as the main drive. Drive C boots fine (however I did notice that there is no progress bar before the Windows loading screen as there is when drive A tries to boot), so I went to My Computer and opened drive A in explorer. I can access all of the files on drive A except for the files in "Documents And Settings/[my user name]/" since they are locked.

I then booted from the Windows XP install disk, and ran in recovery mode. I tried running DSKCHK but it hangs at 50% with no errors reported. I also tried FIXBOOT. Disk A still doesn't boot. By this point I don't know what to think.

Since I was also getting the "CPU has over speed errors" I figured it might also be a hardware problem on my main system. So, knowing that disk C boots perfectly in my backup system, I hooked up drive C to my main system to see if it would boot there. I booted my main system again and discover that disk C won't boot on it! It just restarts itself like it does with disk A.

Now I'm really weirded out... my main system will boot drive B with Windows 98, but won't boot disk A or C with XP. My backup system will boot disk C but not disk A.

I now have absolutely no idea what to think....

I've already reset the CMOS and swapped out different configurations of memory in the main system, but neither helped.

So basically:
- Drive A won't boot on either system
- Drive C boots on backup system but not on main system
- Drive B boots on main system (I have yet to test it on backup system)
- I can access the files on Drive A by booting Drive C on the backup system and opening Drive A in explorer

I've never encountered anything like this before, and any help would be greatly appreciated!!!!!

Have you ran the hard drive's diagnostic test's yet. You can find all of them here. http://www.ontrack.com/jumperviewer/index.asp. As well would be benificail to do a memory check with this program.. http://www.ticalc.org/archives/files...o/61/6146.html.. Let it run for a good half hour if you can get it to boot up all the way. What size psu do you have in there?