Vista not booting in any mode

Hi all. Please go easy on me! I am a novice and this problem is really driving me mad!

My Vista 64 PC crashed earlier today. It wouldn't boot back up, and had an error message saying "Windows failed to start. A recent hardware or software change might be the cause". It asks for the install CD, but i haven't got one. There are no in-built options in F8 on start up, other than to choose the location of the install CD.

I tried to boot in safe mode, but only get a black screen with a mouse cursor. Ctrl+Alt+Del etc do not work.

I therefore downloaded the NeoSmart Recovery Disc. I have run the automated repair several times but without success. I have also tries using a restore point but it says there aren't any! I also don't seem to be able to type anything into the command prompt window that will be accepted. My only HDD is C:, but the command prompt starts with sh4.2#. I'm not sure if this is relevant.

I am currently transferring photos etc from my C: onto an external HDD , so at least they will be safe, and I guess I that shows that my C: is working.

I am fairly confident that if i can get it to boot in Safe Mode (past the black screen!) that i will be able to disable whichever device is causing me the boot issues.

Any advice would be much appreciated.

Thanks in advance.


Peanut gallery guesses;
What is your security software? Can you run a scan from the installation disk? I'm guessing that you have an operational system available so you can download a scanner and see if anything shows up.
How about your backup solution? I know Ghost has a recovery disk that you can use to boot the system.
Keep us posted