Service Pack 1 Error: Trust_E_NOSIGNATURE(0x800b0100)

Welcome to the forum.

It would be a good idea if you told the experts just what the name of this registry fixer is, it's never a good idea to use one Windows 7 is very capable of looking after the register itself.

It's possible the download was corrupted, please post back with as much information as possible about the problem like what happens after the download and why do you say it's not working, remember we can't see your machine so have no idea of what you have running or what it is you see.

Advanced System Care is a major source of problems for Win7 - it doesn't seem to have a clue.

I suspect that it has disabled one of your services - if not entirely uninstalled it.

Please open a command prompt, and type the following commands

SC QC CRYPTSVC
SC QUERYEX CRYPTSVC

copy the output to your reply.

Good - at least that service is still functional!
First run CHKDSK and SFC....
Click on the Start button
type in the Search box
CMD.EXE
right-click on the only file that is found
Select Run as Administrator
- the Elevated Command Prompt window should pop up
At the Command prompt, type
CHKDSK C: /R
and hit the Enter key
You will be told that the drive is locked, and the CHKDSK will run at he next boot - hit the Y key, and then reboot. The chkdsk will take a few hours depending on the size of the drive, so be patient!

After the CHKDSK has run, Windows should boot normally (possibly after a second auto-reboot) - then run the SFC

SFC -System File Checker - Instructions
Click on the Start button
type in the Search box
CMD.EXE
right-click on the only file that is found
Select Run as Administrator
- the Elevated Command Prompt window should pop up
At the Command prompt, type

SFC /SCANNOW

and hit the Enter key
Wait for the scan to finish - make a note of any error messages - and then reboot.

If the SFC scan reports that it couldn’t fix problems, please upload the CBS.log file
Then run the CheckSUR Tool - Description of the System Update Readiness Tool for Windows Vista, for Windows Server 2008, for Windows 7, and for Windows Server 2008 R2 - and post the CheckSUR.log file

(it may be a good idea to zip both files before posting - that can get quite large :) )

You have a number of problems there - mostly to do with .NET, I think...
Unfortunately, I don't have the experience I'd like with this type of problem - and our resident expert is unwell (Richard - get well soon, we need you!)
I would recommend that you request support from MS - it should be free for SP installation assistance.
https://support.microsoft.com/oas/de...direct=1&sd=gn
(with any luck that link will work - I'll try it myself in a tick :) )

[edit - seems to work for me, at least]