Windows 7/8 - restore default task manager?
Solution 1:
Delete the registry following registry entry:
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\taskmgr.exe
Just tested it with process Explorer. The entry doesn't exist on Windows 7, unless I select "Replace task manager" within Process Explorer.
Solution 2:
I followed the instructions in this post and I'm back to stock now. So it was sort of a two step process,
Uninstall Process Hacker
Then run Process Explorer and do the replace task manager option twice.