It's a little difficult to follow your post - but the BSOD you were seeing is related to the integrity of your system, in particular security settings. The BSOD is Windows flagging that your system has become "non-trusted", and that it's no longer able to verify that essential files have not been modified.
Changing permissions for system folders could be a possible reason for this. It could also be a third party virus that made its way onto your system, and disrupted some system files.
We would encourage you to keep AV enabled on your system at all times. Even trusted websites can be hacked and inadvertently distribute malware, and you're taking a lot more risk than most consumers by still running Windows 7.
Well, if the installer folder is defect you get other faults. As I told the files were ok and add. replaced from a running 7 system but no change. So the files responsible for the suveillance are defect, faulty or lacking. Strict logical. But that you come to the roots and reasons.
Lots of freaks say you do not AV software if you behave correct. I tested it and never have problems.
But if a good scanner would repair. And even if the scanner is not successful you have a backup.
Some times a make a backup every day.
In this thread the system was running even with the faults seen by event viewer.
Because the system is some years old it works fine and is faster than 8.1 or 10.
10 speed was improved after the last upgrade.
But 10 get got faulty updates in the past, see German c't.
So I do not like MS, I am more an MS hater.
Sometimes you repair your PC more than use it and lose time !
I need it for all my work no gaming no fun.
In former times in internet forums I encountered more specialists.
Today in Germany you only see make a recovery, make a new installation, use chkdsk, use sfc.
But not much more.
Rare people analyse the system and the faults.
But this should be done though take time, energy and thinking.
If you have one problem not solved by recovery and backup same problem can emerge a 2d time.
So analysis and effective repair would be best.