exe cant open

Hi , I changed in the regedity editor the exe file key , and now i cant open any exe file , even the regedit i cant open or cmd too , I tried anything (also reset to an early saving of the pc i cant) I dont know what to do please help , ill be glad if someone will find the solution. Also i...

All started with recuva I recovered some file but net protector resulted it as virus then it could not be open so I deleted all files related to recuva but later wished to reinstall but when I opened it showed error c:\programmefiles\recuva\recuva.exe couldnt find so then I set recuva as...