Black Screen after login in Windows 7

Hi,

I have an HP G72 laptop that has Windows 7 Home Premium OA. Since March 14, 2013 it's showing me the black screen right after I login. Only the cursor is there and it's movable. It all started when I installed the Win7 Service Pack 1 on March 13. Before that, I would get a message that Scan/Check Disc couldn't be opened because of some recent update but it would go on without any issues. I thought that updating it again would fix that problem. It just game me more.

I tried the System restore via the command line but failed. It said that my Anti Virus (Avast! Free) was running. I have uninstalled the AV and that didn't do anything. The oldest restore point was March 3. It said that it failed to extract a file related to Avast!.

I tried pulling out the Task manager be it wont open.

I can go into Safe Mode and I have tried Startup Repair. It found nothing.

I have done chkdsk/f c: and sfc /scannow but both didn't fix anything.

I need help please.

Thank you.

I haven't tried doing a Clean boot. Will it affect my files?

I created an Admin account and accessed it upon reboot. Instead of a black screen with a cursor, it gave me a (light) blue screen with a cursor. I heard this error sound right after log in but I could see the message. I did the clean boot and nothing happened.

Startup Repair was a bust.

I uninstalled the avast network shield and rebooted. Now, every time I log in Safe Mode, it suddenly restarts to Normal. I'm sorry if I acted with asking first.

Safe Mode is back to normal.

For some odd reason, Avast! Network Shield has returned even after I uninstalled it in the Hidden Devices. Security Processor Loader Driver yellow tag has been removedand Symantec Vista Network Dispatch Driver remains the same.