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I'm having the usual classpnp.sys problems after a motherboard replacement (due to the Intel Sandy Bridge issue with failing SATA ports). Basically the thing goes into a loop where none of the F8 menu options results in a boot.

The strange thing is that it does occasionally boot. I mean very occasionally, maybe 1 in 30 tries. But recently it's literally not even been that reliable.

I tried reinstalling from the Windows 7 CD, but now running that causes a reboot too.

The motherboard is a Gigabyte P67A-UD4 B3 (which is the 3rd rev of the board, I originally had a P67A-UD4.

My only guess is that I should make an Ubuntu disk and see if I can replace the classpnp.sys file from another Windows 7 disk.

I'm trying desperately not to have to reinstall the whole OS, because I've got a lot of stuff installed.

Any idea what classpnp.sys actually does? Or if there's another way to fix the boot?

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Ok, so it booted once again (after about 50 or so retries), I tried a repair install from the win7 disk and got to the "reboot" part and its back to its old shenanigans. –  Phil Carlisle May 14 '11 at 10:56
Ok, so I made an Ubuntu disk and that runs just fine. So its definitely something with the boot process in win7. The fact that it does occasionally work is confusing me. –  Phil Carlisle May 14 '11 at 12:06

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