Yes, Less stress but a lot of time wasted for reinstalling all the software I use...
I don't have a DVD for installation, and I don't have a DVD drive anymore but a bootable USB key should be enough (License is from MSDNAA)
The fact is that those problems are linked because the same error message about CLSID appears under Defender and while I tried to share my HDD over the network.
The last backup is dated of April 17th, so it is too late. Safe mode works fine, and editing files under "Program files" is working.
Since the time I uses Ccleaner I stop using the save option for the registry because I never encountered problem with it.
Today I tried to activate the default administrator account to see if it can solves some problems. It appears that under this account I can run Updates for Windows. It appears that my problem are related to my user account.