In many cases, I was forced to do the hard work curing the computers that are infected because they were with no AV already installed on them at all, yes that's true, many people doesn't know whether their computers need an AV software or not, they don't even know what a computer virus is!
When someone of those ask me for help, I first do an off-line scan & clean.
When I boot the computer, I usually be faced with the same thing every time; the virus made some system restrictions in order to make himself hidden, those restrictions are usually the following :
1 - Disable Ctrl+Alt+Del >> so the user can't see the virus and the other running applications!
2 - Disable Folder Options >> so the user can't set the option to show hidden files!
3 Â–Disable Regedit >> so the user can't see what is going on in system startup!
Unfortunately, AV Softwares have nothing to do with these restrictions and do nothing to re-enable them!
Until AV softwares come with such tool in their next versions, here, you'll find a tiny tool that does the work for KAV, it Re-enables all what the virus had disabled, and brings every thing back. I designed this tool and published it FOR FREE for every one need to use it!