Black Screen after login, explorer.exe faulty, usual fixes dont work

[MildlyExas]

Hi! I'm not sure this is the right section, but since a Virus started it all, I figured it is.

Short story:
-got Virus, got rid of it (probably)
-used ccleaner to "clean" registry, which screwed it up (probably)
-now get blackscreen after login, explorer.exe doesn't start and crashes 5 seconds after starting it from task manager
-same in safe mode
-everything else seems to work
-tried most fixes suggested by googling the problem (win startup repair detects no problem, shell of winlogon reg key is "explorer.exe", sfc /scannow tells me nothing is wrong.

Complete story:
I have Win 7 home premimum 64 bit with all updates. It was preinstalled on a custom built latop from a merchant in Germany

The other day, I got a trojan virus from foolishly running an executable. Its attempt to connect to the internet was blocked by my firewall (Comodo) and Microsoft Security Essentials identified and deleted the virus.. I checked online whether any additional removal steps are necessary for that trojan and according to microsoft, that is not the case.

Still, I decided to do what I did years ago with Xp in such situations: Download a battery of scanning/removal tools to be sure.

I started with ccleaner and unfortunately did a registry cleaning, doing a back up for the first run. But then I rescanned and kept fixing reg issues till none where left. I did not create backups for those additional runs of ccleaner.

When I rebooted my computer, I ran into my current problem: After login, I only get a black screen. No explorer. I can conjure up task manager and run processes from there, but not explorer.exe. When I run explorer.exe, it appears in the processes but then vanishes after 10s seconds. If I try to see its properties in task manager in that 5-10s window, taskmanager crashes.

Things I've tried (using an usb which I accessed with firefox, now I have a portable file manager though):

-safemode. Same problem
-restoring registry with the one backup I made before running ccleaner. no result
-checked whether the entry in the shell of r winlogon is only "explorer.exe". it is
-windows start up repair. Says nothing wrong
-sfc /scannow. Says nothing wrong
-scanning for viruses using MSE. nothing found
-scanning for malware using superantispyware. nothing found
gonna try malwarebytes, spypot search and d and tdsskiller (a rootkit remover from kaspersky) later, but it seems like that's not the problem

one last option i found was

I was able to narrow down the reason. Windows Management Instrumentation service is the culprit which is stopping the windows desktop/taskbar from loading. I went to msconfig and disabled it resolving my issue.

for a problem very similar to mine (explorer exe vanishes after 5 seconds)

But other than that I'm out of ideas. Does anyone have an idea as to what I could do? Since win 7 came pre installed with drivery and everything by the merchant, I would hate to have to reinstall windows 7. The chance I get everything working seems remote.

 

[ThrashZone]

Hi and welcome to SevenForums,
Review this although you've already tried through task...
There's link to see if anything there helps,
http://www.sevenforums.com/general-discussion/368888-windows-7-black-desktop.html

What exactly did you block with your firewall ?

 

[MildlyExas]

I've already done everything mentioned there without success...
except system restore points, i dont have any

the firewall blocked outgoing network traffic from the trojan which microsoft sec ess then deleted

 

[ThrashZone]

Hi,
Thanks for looking at it,
Can you make a new administrator user account to test in ?

 

[MildlyExas]

I don't think so. Control panel seems to rely on explorer.exe. when i type 'control' in cmd nothing happens but
in the task manager i see that explorer.exe, control. exe and WerFault.exe appear and vanish after 10secs

is there another way to create a new user?

 

[MildlyExas]

ok managed to create one by spamming control in cmd safe mode. then i had like a 7 sec window to create a new user before explorer exe crashed. took me a few tries but now i have another admin acc

but it has the same problems

 

[cyrilhubert]

My advice is that you need to re-install your Windows 7 again. The registry cleaner deleted the started config together as the backdoor trojan tricked all of us (software inclu.) to delete all the functioning registries.

 

[cyrilhubert]

sometimes our system reserves also get infected thanks to dll that got loaded during startup.
The whole HDD got to be formatted.It's a very troublesome task.

 

[Borg 386]

Not that it helps now, but in the future consider making a system image backup on a regular basis. That way if something like this happens again, you can restore to the time the image was made.

http://www.sevenforums.com/tutorials/663-backup-complete-computer-create-image-backup.html

http://www.sevenforums.com/tutorials/675-system-image-recovery.html

Also, this tutorial may be helpful.

http://www.sevenforums.com/tutorials/668-system-recovery-options.html