Task manager doesn't work

Hello all!!

I'm having an issue I can't solve.
Since 2/3 weeks I'm having problems with my taask manager.
ctrl alt del task manager pop-up doesn't work as ctrl alt esc.
After searching on google and trying to reactivate it(thought it was a virus due to my research) it still doesn't work.
The problem is that windows isnt showing any error message, it just doesnt pop up.
Also I've read about sfc/scannow (if im correct).
I did that but then there was a way to convert my crashes to an .txt file but when I did that the file was empty.
CMD told me that there were system problems but I can't find out what the problems are.
Also watching youtube-videos on HD(720p and 1080p) seems to crash the vids after a random time.
This looks like an hardware error but coincidal this showed up around the same time.
One last thing is that everytime I start up my computer windows asks to scan my drvies for space(if i'm correct).
This happens every time and most of the time scans both my drives, but sometimes it's just C: or E: (C is my windows drive and driver stuff, E: is documents and other stuff).
Thsi occured rougly about 2 days after the taskmanager problem started.

I know this is a long post, but i'd rather show all I know than to keep posting things I already knew ^^

I hope you guys know how to help me!!

I knew the command mistyped..
CTRL ALT SHIFT method didnt work.. thanks for feedback^^
Done with the sfc/ scannow thingy: Damaged files have been found, but couldn't all been repaired.
Details can be found in CBS.log windir/Logs/CBS/CBS.log..
What must I do to fix the problems?

Hello all!!
Sorry for my late response, been bit hectic with work..
Thanks for all the help.
sfcdetails worked this time, attached it.