Earlier I installed some software then my pc got infected and every file in my pc changed to this type of file : ETOLS File (.etols) I installed new widows 7 ultimate x64 nothing happened I installed anti virus no thread were found I tried Avast, Kapesrsky,CCE Suit and many other, Still my files has that type of file : ETOLS File (.etols) Even videos softwares and audios got infected I tried Everything in my power but cant fix those files.
If I try to change the extension then videos does not play I tries Gom player,K lite Codec,Vlc
there is no information on google about this type of file even google can find this.
what Should I do

If I try to change the extension then videos does not play I tries Gom player,K lite Codec,Vlc

there is no information on google about this type of file even google can find this.
what Should I do