weve already established its a problem with your PC

Best option - fix or just reset your PC back to a proper working state

There really isnt much else we can say other than until you solve it, do...

Open resource monitor and check what process specifically is using it.

if windows explorer is hanging then its "definately" a issue with your pc

boot into "safe" mode and remove the program that way

then clearly something is wrong with your pc

its prob not in the "applications" part of task manager. Look further down

steam for example, appears way down the bottom when it does this

Currently it works for me on Windows 7, 8.1 and 10, all Pro x64 editions, so something on your end, try running as Admin? Also what do you mean open in "system"?