Windows 7 broken: can no longer log in...

Kaktussoft said:

Did you do a "system restore" to a date prior to possible infection?

Well... hard to tell, I did a system restore with a restore point dated from the day before, so one could conclude that the infection occurred that day, but it's difficult to be sure.

Kaktussoft said:

try an earlier restore point.
and perform a malware check

Sure, I'll try earlier ones.
About MS System Sweeper, did you use it already?
Tried to burn a DVD from 2 machines, but, in both cases, it told me that it couldn't found any CD or DVD
Same issue with USB key from one of the machine, and on the 2nd it told me that it will use A:, while it is a obviously a diskette drive and that my USB key is in E:...

TerDale said:

About MS System Sweeper, did you use it already?
Tried to burn a DVD from 2 machines, but, in both cases, it told me that it couldn't found any CD or DVD
Same issue with USB key from one of the machine, and on the 2nd it told me that it will use A:, while it is a obviously a diskette drive and that my USB key is in E:...

OK, my fault, once run elevated it works to burn my DVD
Burn in progress...

Kaktussoft said:

first try a restore point from a few days prior to infection.
after that try ms system sweeper

Why this order? Actually it is currently scanning. If it can found something and fix it, I would prefer to get my Windows back to the most up-to-date state in terms of settings & installed apps.

Kaktussoft said:

Going back in time "software and settings" is better then destroying virus/malware using tools. You go back in time so virus is almost sure gone.

OK, I get your point.

Kaktussoft said:

Tell me if sweeper finds something, and if so tell me what it found.

Sweeper (actuall Windos Defender Offline) found 2 issues rated as "serious":
- Trojan/Java-openConnection.01
- Exploit/Java-CVE-2010-840.EX
Was puzzled reading this...indeed FMPOV, don't think these are the actual issue affecting the logon process, considering they are bot Java-related....
Anyway, tried to reboot in safe mode and of course the same BSOD, so tried to repair fom within RC, still working...

But, don't think MS is the best for malware fighting, so will try some of the rescue CDs provided by most AV vendors.

Work through these steps for Troubleshooting Windows 7 Failure to Boot - Windows 7 Forums.

Double check infection is cleaned up using Malwarebytes if you can get into Safe Mode, or another bootable AV given in blue link tutorial.

Then repair damaged System files by going through the steps given which will assure you've done all you can.

If force to re-image or reinstall then this time keep your Programs on the same partition as OS. Since they write registry keys to OS they should be contained within it, and in the same backup image which is the modern replacement for reinstall. Backup Complete Computer - Create an Image Backup