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I'm running Win 7 x86 on a Lenovo Thinkpad Z61m in dual boot mode with Win XP, both OSes are running on separate partitions. I have a faulty battery and if left unplugged my laptop shuts usually down within 10 minutes. Last night, it shut down due to this, but after plugging in AC power and starting back up I'm stuck at the "Starting Windows" screen, I'm unable to boot into safe mode or into recovery mode(XP boots fine).

I believe I had installed some Win 7 updates the same/previous day. From one of the boot options I was able to see that Windows 7 is getting stuck on CLASSPNP.SYS

How can I go about fixing this?

I do have a complete Win 7 Restore CD that I created after setting up my machine, I'm unable to boot into this either.

Please help!

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migrated from Oct 26 '09 at 13:20

This question came from our site for system and network administrators.

It's likely that the file was in use during shutdown, causing it to become corrupt. If that's the case, then the fix would be to repair this and any other corrupted files.

First, you'll have to get to a command prompt. Can you boot into safe mode w/ command prompt?

If so, use SFC (System File Checker) to fix. Once you get to a command prompt, type:

sfc.exe /scannow

Source: Microsoft Technet - Using System File Checker to Fix Issues

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What if I am unable to boot into safe mode with command prompt? – Roy Tang Sep 26 '10 at 12:04
Booting in Last Known Good Configuration helped me. I was also not able to boot in Safe Mode. – 62316e Oct 12 '11 at 10:56

I had the same problem on my Thinkpad W500. The problem is evidently that an update makes a change to classpnp.sys that is incompatible with the Thinkpad's hardware. The solution is to replace the file with an older version. Unfortunately, I'm not sure where to suggest getting one.

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That may not be the only file that needs to be replaced. I think a repair of the OS should be done at this point to fix the files. – SoftwareGeek Feb 26 '10 at 18:24

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protected by Jeff Atwood Jun 7 '10 at 6:44

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