Get malwarebytes and reformat your hard drive
Need help!!! PC Hacked
try to install new win
Download malwarebytes, restart computer into safe mode and perform a full scan. If you don't find anything just format the hard disk and install a fresh copy of Windows 
If you know which program it was, you can use RevoUnInstaller to delete everything related to that file, it clears EVERYTHING, also changed Regedit entrys etc
Worst Case
Dariks Boot & Nuke (dban)
It completly wipes your harddrive, if there is no physical damage, its pretty much like it comes fresh out of production
But of course you will have nothing left then, in case you got important files
To all Geniuses, even a reformat wont help in some cases
A reformat does not really delete all files, there are some parts which will stay, because you are currently unable to even see its there. And it is possible to place malware in those places, so the reformat wont affect them, thats why i recommended dban above.
Anyway, thats the 1% that are ZeroCool like, it helps in 99% of the cases, i still would get sure
Worst Case
Dariks Boot & Nuke (dban)
It completly wipes your harddrive, if there is no physical damage, its pretty much like it comes fresh out of production
But of course you will have nothing left then, in case you got important files
To all Geniuses, even a reformat wont help in some cases
A reformat does not really delete all files, there are some parts which will stay, because you are currently unable to even see its there. And it is possible to place malware in those places, so the reformat wont affect them, thats why i recommended dban above.
Anyway, thats the 1% that are ZeroCool like, it helps in 99% of the cases, i still would get sure
just turn on the antivirus ..
