Using LogMeIn after restarting the computer I was getting blank screen (blue), with a mouse cursor, nothing else. This happened to the computer that was infected with several viruses and after cleaning and rebooting this was a result. I coudl use CTRL+ALT+DEL to start Task Manager, but from there I could not start Windows Shell (explorer.exe) - the error message was that the file is not found, even though I could navigate to C:\Windows directory and see this file.
There are 2 registry keys in the registry that are causing the problem. It affects the explorer.exe and iexplorer.exe files.
This is the key that needs to be deleted…
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\explorer.exe
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\iexplorer.exe
Once these keys are deleted the desktop and internet explorer should come back to life.