errorloading OS

Pulled out my desktop box yesterday to try a different GPU. When I went to boot, I got this message: error loading OS.

This is an old IBM Intelistation Pro Z with an SCSI boot drive. I reinstalled the old GPU, I checked all of the cables and reseated them. No change. I checked the BIOS but everything seems right there. It recognizes the drive.

Then I booted with a linux live boot CD. It could find the drive, and everything was accessible on it. I have a WIN7 System Recovery Disk, which I ran. I had it do an Automatic Repair, twice. Nothing changed.

Next I ran a Hirens Boot CD. With that I clicked on Boot from Hard Drive, and it started right up and everything seems to work fine. I reboot without the disk, and get the same error.

I am guessing that I somehow corrupted the MBR when I was moving the computer around. Can I repair this? Or do I need to reinstall Windows? This computer is running Win 7 32bit, from an upgrade disk. It was installed several years ago.

I have never done a backup image of this drive, though I do have a recent back up of the files on the drive. Most of my documents and photos are on a separate, second drive on the computer. I will also check and replace the battery on the MoBo while I am doing all of this.

 

When I got in with Hirens, I did a disk scan, and it turned up no major errors. I also ran the AV scan that is on the Win 7 System Recovery Disk. It found a few things, such as 4 instances of worm.Palevo, which it removed. I wonder if that could have caused this.

 

Found the issue. My Mobo battery was weak. When I unplugged it, the bios changed the boot sequence of hard drives. I have 3 in this computer, and the drive with Windows moved to the end of the list.