Windows 7 - Logon Screen is blank most of the time

Hi!

After booting my machine (Sony VAIO Z2) the logon screen appears, but just the background. Everything else is missing. Only option I do have is forcing the notebook to shutdown by pressing power-button for a few sec.
This does not happen all the time. Sometimes I'm able to boot/logon normally a few times in a row, sometimes I have to reboot very often just to finally get to the (non-blank) logon screen.

I've seen that there are already a few (old) threads on this topic in this forum, but none of them seemed to solve the problem I have. I don't want to be reinstalling all over again.

I've already tried to deactivate some services like Novell Client and fingerprint reader, which both interfere in the logon process. But nothing changed.

Booting from a Windows 7 DVD and using startup repair function hasn't changed anything either.

You can execute an SFC Scan (Tutorial) with your Windows Installation DVD, if this is caused due to windows corruption. You should also do a malware scan whenever you are able to boot windows, with your current antivirus or with Malwarebytes.

Just to be clear I ran the command correctly:
"sfc /scannow /offbootdir=c:\ /offwindir=c:\windows"
Where c:\ is my system drive. The scan took quite a while, but didn't find any errors. (ran it twice)

Already made a full system scan with MSE and Malwarebytes. No items found.


*edit*
I've just recognized that I wasn't able to successfully disable fingerprint reader, because it still works.
(I've disabled "TPM Base Services" and "TrueSuiteService" services)

Have you attempted a clean startup? Troubleshoot Application Conflicts by Performing a Clean Startup.

^Yes I did follow STEP ONE and STEP THREE. None of it solved the Problem.
Just that STEP THREE (normal startup) screwed up my windows boot manager and I had to run a startup repair from the Windows 7 DVD, which got fixed by that. But original problem remains.


But just out of curiousity:
How should that troubleshoot guide fix errors services like the fingerprint reader might cause, as the fingerprint-reader service is an Microsoft service as well (like 90% of the services are Microsoft services and therefore always enabled following the troubleshoot guide)?
So imo that's a pretty useless troubleshoot guide.

It will fix problems if third party applications or services interfere with Windows services operating properly. Windows services have been tested thoroughly and do not cause problems unless there are third party programs, drivers, or hardware problems causing them to fail. They can also cause problems if the Windows files themselves are corrupted, but since sfc came up clean, that is unlikely. The only other possibility (assuming your hardware is fine and drivers are all fine) is the registry is damaged. Have you at any time used an optimization tool to clean the registry? VAIO Care perhaps?

I'm not sure if you got my previous post, but lots of third party service are marked as Microsoft services and therefore all keep enable when checking the "hide alle Microsoft services" checkbox.
Or am I wrong here?

What do you mean with "clean the registry"? I've done some registry tweaks which are advised in the"windows 7 and ssd optimization" tutorial from the forums here.

Ah, I see what you mean. I thought you meant the services that come built into Windows, because most of the services are going to be Microsoft unless you have a ton of programs installed on the computer. If you know it is a third party Microsoft service or part of a program that is not built into Windows, then you can try disabling it. The reason Microsoft services are excluded in that tutorial is the average Joe does not have the experience with computers to distinguish between Windows 7 level services and services installed to run over the top of Windows 7. Those tutorials have to be written with all users in mind, and the experience levels range from knowing nothing to knowing a lot about computers. The gurus would not want to tell the average Joe to turn off a Microsoft service that made Windows stop operating altogether.

Registry tweaks provided by gurus on these forums are fine as they were found by users on here who have a lot of experience with registry maintenance and changing. I meant the automated programs should be avoided; programs like TuneUpUtilities, CCleaner (the registry cleaning part of the program), PerfectSpeed, etc.

well there are like 100 services. Hard to distinguish necessary ones from those ones which can be disabled.

No, I haven't used tools like that. Always doin regtweaks myself. And all of the tweaks I applied to this notebook were from these tutorials.


So, what now? :/

How long has the problem been present? Have you attempted a restore point to before the problems began?