TrustedInstaller deleted

Did you try System Restore and compare the Services settings Defaults in the tutorial Shawn linked?

You may get enough relief from those three scans, but if there are irreparable System files and problems persist, then I'd consider the Repair Install which keeps your programs, files and settings in place and reinstalls the OS. Make sure to read over Shawn's steps closely as you'll need to have a readable Product Key on the COA sticker and there will be a few settings you may need to set back.

If your neighbor's installation disk doesn't work, how to obtain media for your licensed version is discussed in Step 1 of Clean Reinstall Windows 7 including how to unlock other versions from the same disk to make your own.

gregrocker said:

Exactly how was it deleted from services? It might be disabled but how was it deleted?

Brink said:

If you meant "TrustedInstaller" for permissions and owner instead, then this below should help. :)

TrustedInstaller - Restore as Owner

Well, finally I repaired the Firewall it had nothing to do with TrustedInstaller, my PC had some Trojans. After removing them I repaired SharedAccess and BFE and now it works again.
I still have the problem "0x80070424" with my Windows-Defender and I still can't Update my Windows, but I think I will repair that soon too. (Windows-Update has no error-code, it just says that it cannot Update because the service isn't running and maybe a restart could help. (not original text, it's in German and I can't translate it exactly))

If you have some ideas how that could be fixed (Windows Updater&Defender) please reply.

Thanks for your support :)

Bertie

Have you run Malwarebytes and SuperAntiSpyware scans again and they come up clean?

What are the results of SFC /SCANNOW Command?

Even if it repairs the damaged System Files, I also would skip to the Clean Reinstall Factory OEM Windows 7 which explains how to get and keep a perfect install for factory installed WIn7 on your Medion PC.

RolandJS said:

Are you running any 3rd party anti-virus or security suite? Many of them disable and keep disabled Windows Defender.

Brink said:

Bertie,

When it comes to viruses, I prefer to format and clean install Windows.

gregrocker said:

Have you run Malwarebytes and SuperAntiSpyware scans again and they come up clean?

What are the results of SFC /SCANNOW Command?

Even if it repairs the damaged System Files, I also would skip to the Clean Reinstall Factory OEM Windows 7 which explains how to get and keep a perfect install for factory installed WIn7 on your Medion PC.

What means 3rd party? I only have Avast! Free Antivirus as far as I know.

Shawn, do I have to backup my files on a external hard drive or can I just do that without saving and I will still have everything after that?

Yes, after they've found Trojans and I put them in quarantine, I ran the scans again on both and they didn't find any viruses. The results of sfc /scannow is: Nothing found. All should be fine but it still doesn't work.

Thanks for your help again

Bertie

Brink said:

Bertie,

Yes, you'll need to back up anything that you do not want to lose. A clean install will delete everything.

Okay but the problem is 1rst I have no external hard drive and 2nd it's not really necessary is it?
I'd just be happy if the Defender and Updater work again, that's all I wanna have. Maybe I'll do the clean install later.

I'd strongly recommend as has Shawn that you Clean Reinstall Windows 7 since you'll never know for sure it's completely clean or undamaged after heavy infection even if the scans come up clean.

If you would prefer to try to repair, and SFC /SCANNOW Command does not show unfixable System Files after 3 tries, and you don't want to run a Repair Install which often fixes problems like this, then try these to see if you can get Updates functioning:

System Update Readiness Tool fixes Windows Update errors in Windows 7
Windows Update - Reset - Windows 7 Forums
Windows Update Posting Instructions - Windows 7 Help Forums

Keep in mind that Windows Update may require plenty of Restarts and even Shutdowns if there are Updates queued with a "!" on the Start Menu Shutdown button. This is how to clear them if they bunch up or start erroring.