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Windows 7: Windows hangs on boot.

13 Jan 2011   #1

Windows 7 Ultimate
Windows hangs on boot. Black Screen. CLASSPNP.SYS on safe mode

Hi everybody I was hoping you could help with a perplexing situation I have on my hands.

Since a few hours ago my Pc wont start.
When i rebooted it stayed for ever on that glowing-pulsing quad-colour thingy that windows 7 shows briefly while booting, and never moved ahead to get into windows desktop

After a couple of failed attempts I decided to try logging in at 'safe mode'. even this didn't work. The boot sequence seems to be hanging after trying to load the CLASSPNP.SYS driver.

and yes i read the various posts and Windows 7 hangs on startup this guide as well.

So i decided to use the Win7 disk to perform a repair. I even have a rescue disk, actually two as I set the last one up just a week ago, and i even have a full image backup on an external disk, to restore if everything else fails.

problem is, when i try to boot from the DVD or the repair disk, the following happens:

I get the option to boot from the DVD. >> i choose to do so.
Then i get the usual message that files are being loaded or copied
Then i get the small glowing bar that moves left to right, the usual image preparing us to enter the setup environment and then:

BLACK goes the screen, and the NUMLOCK key locks ( you cannot change ts state..) which is usually a clear indication the Pc has hanged badly.

I tried with two different windows 7 disks.
also with two windows 7 Repair Disks.

it is always the same.

Then I tried disconnecting everything from the Pc apart from the boot SSD.
even all external connections.
USB, eSata, even the mouse and left only a keyboard.

The same things is happening

I even changed keyboards, back to a plain vanilla Ps2 KB.


I'mout of ideas atm, any help would be greatly appreciated.

I would like to point out that till 3-4 days ago the PC was working like a clock for around 3 months.

Then i started having frequent problems with my Bluetooth Wireless Logitech keyboard and mouse. The signal would get lost, even though both had batteries over 50%.

sometimes i was able to correct this, by having the Logitech software re-detect the keyboard and mouse by pressing a reset button on the usb-blue-tooth receiver.

4-5 times I had to hard-reset the Pc though as this didn't work and i was left with a non-responding Pc on my hands. I'm guessing these 4-5 hard resets might had something to do with my current problems, even though all these stopped since yesterday when i swapped the wireless keyboard for a regular USB one.

My System SpecsSystem Spec
14 Jan 2011   #2

Windows 7 Ultimate

hmmm... anyone?
My System SpecsSystem Spec
18 Jan 2011   #3

Windows 7 Ultimate

finally solved this by removing the SDD i was booting from, attaching it to another computer with windows 7, replacing the CLASSPNP.SYS file with one from that computer, and reataching it to the original computer, AFTER cleared the BIOS in my machine.
My System SpecsSystem Spec


 Windows hangs on boot.

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