Windows 7 Black screen with movable cursor

[Bvision]

Hello,
My computer starts to boot up as normal, shows the 4 colored dote resolving to the Microsoft logo followed by the light blue screed with usual Microsoft decal then the screen goes black and all i have is the cursor. the cursor moves as normal but that's it. Ctr-Alt-Del brings up the light blue screen with the usual options and if I select Task Manager it appears but still with a black screen behind.
I can reboot in safe mode and I get the normal Windows screen. however my Anti Virus (Bitdefender) will not load. trying a system image restore has produced the same result.

 

[soundguruman]

system conflict...
what you can try is setting the bios to boot the CD DVD first...
put the windows 7 disk in the drive, and select "upgrade"
The upgrade replaces the OS files but does not erase the personal files.

All your personal stuff is left intact while the operation is renewed. The computer
will restart several times while installing the upgrade.

When the OS files are set back to default this will usually make the system
work again. Unless there is a hardware failure, or perhaps malicious junk
in the drive.

After you get the system to boot, immediately back up all your personal
files to a CD DVD thumb drive etc. or an online backup if you can get that far.

In the case where the OS is not recoverable, a virus may be on the drive, etc...the data can still be recovered and saved by installing the drive as a second drive on a functional computer. The second computer should have a professional antivirus that is updated.

OR a computer shop can do that for you. They charge about $200...