Well have a nice 3 day weekend I come into work to find our second register that runs quickbooks POS giving me the "DISK BOOT FAILURE, INSERT SYSTEM DISK AND PRESS ENTER" error message. I think the power went out and screwed something up. So I reboot just hoping it will work, and after some loading I get a black screen with white text and the the error message: "Windows could not start because the following file is missing or corrupt: \WINDOWS\SYSTEM32\CONFIG\SYSTEM" Ok so I find a nice guide that tells me how to replace the offending file from the xp pro install disc. I try to do this and I get an "Access Denied" Error. So i see its recommend to try running chkdsk /r from the recover console and try again. So I do that, and reboot. I then start getting a BSOD with "Unmountable Boot Volume". So from the recovery console I ran fixmbr and fixboot. After that I started getting a BSOD with "WINDOWS\SYSTEM32\CONFIG\SYSTEM" error. I copied over the correct files to fix than, and after rebooting I got a BOSD with "WINDOWS\SYSTEM32\CONFIG\SOFTWARE" error. Copied that file over, and the BSOD went away. But now when I boot it goes to the windows loading screen, then after bit the screen goes blank and stops. If I boot into safe mode it stalls at "mup.sys". A quick search recommends going back into the recover console, finding agp440 service and disabling it. Unfortunately I can't find the agp440 service listed when I use the listsvc command . I did some more searching, but haven't really found a solution for this. So does anyone have any bright ideas? And I really don't want have to reformat this computer. Its not an issue of data loss since its the 2nd register, and running Quickbooks POS as a slave client, all the data is stored on the server register. But reinstall Quickbooks is such a pain and last time I spend 4 hours on the phone with their help trying to activate Quickbooks, the entire time treated as if I was trying to steel their software -_-.... So if I can avoid reformatting it would make my life that much wonderful. Also attached is the hardware profile for that machine generated by PartionMagic found on the UBCD. And thanks in advance for any help offered. If you need any more info feel free to ask.