Encountering stop errors, problems installing windows xp, random reboots

Ok, I'm at my wit's end here...

I have recently upgraded to a new motherboard (Asus A7V600) and processor (AMD Athlon 2600+ XP with a 333MHz FSB) and have encountered several problems, including trouble installing windows xp, stop errors, and random reboots.

At first, I left the clock settings at the default levels because I didn't know what to change them to (This caused the system to register the athlon as a 2600xp but running only at 1.4ghz).  I formatted my 80 gig drive no problem (separating it into one 15mb partition and the rest), and windows xp installed almost without a hitch - several times during the file copying process it gave me the message "setup cannot copy the file: <filename>".  Pressing retry solved the problem.  Once I had windows installed, I installed drivers for hardware (USB controller, RAID controller, Onboard sound, etc.) with the yellow ! beside them in hardware manager.  I used the drivers from the motherboard cd.  

At this point i shut down, connected my second HD with my backed up files on it (mydocuments, etc.) and proceeded to boot up and copy them to the new c: partition.  All of a sudden, random reboot.  I immediately thought it might be overheating as the mobo is set to automatically shut down on an overheat, but it was cool enough (around 50 celsius).  I don't think it was caused by the memory either because it was functioning with no problems in the old 1.4ghz system.  The random reboots continued every time i tried to do anything in windows (copy files, play games, surf).  I decided to upgrade the BIOS to the latest version with no positive effect.

I did some research and found that my cpu settings should be:
CPU external frequency: 166/33
CPU Frequency multiplier: 12.5
Memory frequency: Auto (I have two sticks of DDR 256mb PC2100 at 266mhz in slots 1 and 2 on the mobo)

This hasn't seemed to help.  I changed the settings, tried to reinstall windows and continually get: "setup cannot copy the file: <filename>.  Retrying the file works only for a few, then will not continue past certain files (which are different every time).  Further research I did points to several possible causes including overclocking (which i'm not doing with those settings, am i?), a bad cd rom drive (i tested another one, so i don't think that's the cause) or a bad HD (well, it worked fine in the old system).

Once during the windows install, i received the message "File setupdd.sys could not be loaded. The Error code is 4"

Finally, i've been encountering stop errors during the first install with the old clock settings, and during windows installations.  The error's i've seen SO FAR are: 0x0000008e, 0x00000007e, 0x00000024 with reference to ntfs.sys (have all happened several times) and finally 0x000000d1 (has happened once).  The research that I did on these didn't help.

My guess is that my cpu settings are still incorrect

Please help me!

Thanks