Windows 7 issues

Status:
1. I don't see Accessories in "programs" anymore
2. I am getting a blank page when trying to start IE11 - no error message
3. Unable to search in control panel or windows explorer - just doesn't react, control panel does not have "add or remove programs" anymore
4. I get the error message "Windows cannot access the specified device, path, or file" error when you try to install, update or start a program or file


How it all started:
I tried to figure out why my library books on my nook get "user not authorized" on my second laptop after transferring books using Adobe digital Edition


For some reason I ended up going into "users" folder, properties, security , clicking on "hidden" - and that's how things started to disappear. I was able to reinstate the desktop icons (start - computer - altered settings there) but I am still not able to resolve the issues above.


Tried the threat for adwcleaner, superantispyware,tfc - no success in how IE behaves. I am able to run all this via firefox.


How can I get my system back?! I think it all has to do with privileges but not sure how to fix that...


Any help is appreciated....