No sound

Hello, could someone help me please? about some days ago my audio suddenly became staticy so I decided to uninstall both audio devices on my acer aspire 64 bit 7740 laptop in safe mode and I thought they both would reinstall but I find out that only one of them reinstalled and the other one never reinstalled and is gone and now I have no sound at all and I've tried so many things I even tried looking for the backup audio but I couldn't find it so now I just want my sound back and its been on the no speakers or head phones plugged in stuff ever since