I'm at a loss here. I recently got given old Acer D525 running Windows 7 32 bit that I was hoping to use as a small backup computer. It was running fine until it started slowing down drastically. I'm talking 5+ minutes of waiting after clicking anything. Eventually it failed on boot and went into startup repair which also failed to sort anything out. Since there was nothing important on it I just did a factory restore.
It worked fine until I rebooted, then back to startup repair which again failed due to corrupt registry. I then installed a fresh copy of Windows 7 64 bit and again it ran fine until rebooting and the same thing happened. As an experiment I installed the latest Ubuntu and again it ran fine and failed to boot up with file system errors. I reinstalled Ubuntu and same thing.
I then ran Hiren's boot disc and did ever test I could think of. Everything passed no problem.
I can't figure out why a seemingly healthy system would fail when booting on different OS's.