Corrupt or Misplaced DLLs

[RIOT]

Scenario:
AMD Duron
512 MB memory
Two physical hard drives. One IDE and one SCSI. The IDE drive is 6 GB, contains the XP Pro SP2 operating system (fresh install), and has about 1-1.5 GB free. The SCSI drive is 6 GB and contains the following software:

Firefox
Thunderbird
Abiword with plugins
Avast Anti-Virus
OpenOffice
Picasa2
Spybot S&D
Acrobat Reader 7.0
Easy CD Creator 6
Avery DesignPro
Corel Collage Creator

It has 4.2 GB free space left.

Problem:
Most software on the SCSI drive will not load/open correctly. OpenOffice gives errors about various DLLs. Corel Collage Creator gives an error about the kernel32.dll. Picasa2 doesn't give an error, but won't open. The Easy CD Creator 6 menu will open, but only certain programs will load from it (DVD creator, Disc copier will load; Classic creator, Audiocentral won't load). Avery DesignPro won't load and gives no errors. Acrobat Reader 7.0 gives an error about the core DLLs. Spybot S&D won't load. Firefox won't load.

Avast AntiVirus loads at startup and seems to be running fine. Thunderbird starts, but I have no user information to enter at this time.

Solutions Tried:
This morning I was able to start and run almost every program. Avery DesignPro was the only program that was giving me problems at first. I realized it needed Acrobat Reader so I installed 7.0. Avery DesignPro started running correctly, but Acrobat Reader and other programs wouldn't work. OpenOffice and Abiword stopped working. Re-installed Abiword and fixed it. Tried re-installed OpenOffice, but I can't uninstall it (Add/Remove Programs won't remove it). Tried to re-install OpenOffice over the existing installation, but received errors when registering DLLs. Noticed Picasa2 and Spybot S&D wouldn't load now. Tried Abiword again and it wouldn't load. I installed Inkscape to the SCSI drive, and it wouldn't load. Un-installed it and re-installed it to the IDE drive, and it runs fine.

All hardware is detected and running without problems that I notice (Device Manager isn't showing a problem).

I'm leaning towards something screwy with the SCSI drive or the SCSI card, but I'm not sure.

Any suggestions???

[shamus]

SFC from a cmd prompt?

[RIOT]

SFC from a cmd prompt?

What is SFC?

The computer was recently donated to the lady who owned the computer. I had to take the computer back to her yesterday afternoon, and I let her know that there were definate hardware problems with the computer. She's taking it back to the guy that donated it to her so he can take a look at it. If I would happen to hear what he says is wrong with it, I'll let everyone know.

[shamus]

What is SFC?

System File Checker

Description from MS here (although it just mentions Win98, it's included in all OSs after it): http://support.microsoft.com/default...b;en-us;185836