My brother was playing some flash games on my pc. And he accidentally installed Lavasoft Ad-Aware program. Now I had removed it from control panel. I had gone through some steps mentioned in a article. I was just in a process of deleting left file in the system. Among which I am not able to get rid of ShellExt_64.dll. This file is locked and it is not getting out. What should I do to fix the issue.