Windows hangs on CLASSPNP.SYS - even when using a boot disk.

So I really have no idea where to start, I can usually fix things myself but I can't even get to somewhere useful.

I have made no hardware or firmware or any changes since last successful boot. Mac OS X boots up fine from my second HDD (my laptop has PC architecture, it's not Apple). Removing this second (OS X) HDD and then attempting boot makes no difference.

What gives? If I can't boot from a Windows USB then...it must be hardware related? But Windows was working fine with exactly the same hardware for ages. Plus it's all still recognised in Mac OS X, so nothing has suddenly broken. My 4x4GB RAM SODIMMs are still fine, so is the CPU and GPU, sound card, wireless card...I really don't know what I'm looking for.

I might have to start removing things and swapping them about to see what happens.

Thanks,

Jake

edit: feel free to move to Crashes and Debugging

Hello Jake -

See if this link helps:

My Note on Solutions.: Fix the classpnp.sys problem, Windows 7 SSD macbook

Synopsis: You will need a copy of classpnp.sys from another computer (same architecture 64bit or 32bit).

Regards,
GEWB

GEWB said:

Hello Jake -

See if this link helps:

My Note on Solutions.: Fix the classpnp.sys problem, Windows 7 SSD macbook

Synopsis: You will need a copy of classpnp.sys from another computer (same architecture 64bit or 32bit).

Regards,
GEWB

I will try this, but don't expect it to have any effect as I cannot boot up from a Windows 7 Boot Disk - and the classpnp.sys file on that must be fine? If it has one, I'm not sure how it works but if it can't boot from a genuine boot disk I don't see how replacing this file will fix it.

In fact, this solution involves replacing it using the cmd prompt for a boot disk, so I can't do it that way, though I can just use my OS X HDD or boot from a Ubuntu LiveCD.

Bumping, still no solution and I need my Windows partition as it has my photo organising software on it, and I am rapidly building up a backlog of photos I need to sort. About 1,300 at the moment.