So here's the deal. I was fixing my moms PC this weekend! Major drama! UGhh! Anyway, she's running a Athlon 1.3 Ghz with 2 HDDs. One is a maxtor 40gig (primary master) the other is is 10 Gig Quantum Fireball (Secondary Master). When I first went there and turned on PC it powered on and then shut down before posting. After pulling out everything but the essentials, the pc would post but would freeze when it said something about verify or finding DMI files? Even using a starup disk and getting into DOS, the system would not let me Format the C: drive. I finally ended up taking out the big C drive that I couldn't format etc. I put in the smaller drive. Formatted it with no prob. Installed windows me. Then, after I had the PC all set up, I connected the Big drive as secondary master. I turned on pc and it loaded windows off the small drive no prob. I went to my computer, right clicked the big drive, and selected format and formatted it that way. Then I went through all the trouble of reinstalling windows on the big drive and setting it up as primary master. My question is does anyone have an idea why the big drive was acting that way? Physical problem? Virus? What gives... I have always been able to format before with no problems. Just curious. Thanks.

Just a guess! But I suspect that the 'overlay' program that allows a Bios to recognize an oversize drive was corrupted.

You might see if there is a BIOS update for your Motherboard. MFG's will put them out to help identify and recognize newer HDD's as well as fix other things.