I noticed some errors a few weeks ago and was unable to run chkdsk c: as it would not blue screen, but reboot at one point in the process. This was running chkdsk in windows with no /f or /r parameter.

I was able to copy my data from the drive (Drive C Boot) to a USB HD and last night booted with my Windows XP Disk, went into recovery mode - command line and executed fixmbr.

It warned me that my mbr was non standard and fixing it might leave it in an unusable condition. I ran it anyway.

I then ran chkdsk /p in command line mode and it has been running almost 24 hours and still says it is 50% completed.

It also wrote to the screen:
CHKDSK is performing additional checking or recovery ...

Any suggestions? My next step is to reinstall XP and reformat the drive.

Yes, I fear as much. Is there any 3rd party utility that might to a better job at resurrecting the partition?

When run chkdsk /f c: it tells me that there is a problem with security descriptors.

It's a bad harddrive. I'm running Spinrite on it and I'm getting seek errors and it just went into recovery mode. I'll likely be chucking it in the garbage.

My second bad SATA drive in 3 months.

yeah! not sure if it a sata problem or they are making them bigger [way to big ]instead of better .