Sometimes all aspects of recovering from a virus are also corrupted, that is why they don't work. The only thing you can do is copy all files that you want to an auxiliary drive or thumb drive, format hard-drive or partition that Windows is on and re-install Windows.
I have a Dell Inspiron laptop running windows 7. I had a trojan.zbot virus. I removed all traces of it, but my pc is a mess. IE will open, but immediately says it has stopped working. I tried system restore, but I get an error msg. I tried system recovery, but it won't restart to do the recovery. I also get a msg to install NETAPI32.dll. What do I do?