didn't you post you can't use any browser but Safari but you can do windows updates... windows updates use IE services by default so obviously IE is working.

*** i haven't read the entire thread but here are some things i would do ***

run an updated anti virus like avg + malewarebytes in safe mode then try running IE in safemode. i would also clean out your registry by hand if you know what to look for. i would uninstall all browsers and run windows updates.