I did it because I wanted to install Vienna theme, so I replaced my explorer.exe file with theirs. Also, I backup the original explorer.exe by Copy-Past it to the same directory so it made a file name "exolorer- Copy" in Windows directory. When I restarted the computer nothing appears, and when I try to make a new "explorer- Copy" task it says it doesn't responding for some reason. What should I do? thanks.