Windows can't find explorer.exe

I have had problems with explorer.exe not running.  The machine would boot up however no desktop.  If you tried to run explorer.exe from the task manager nothing would happen.

After doing some exploring, I had discovered that a registry entry was added to the

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Image Execution Options\

The entry was a "debugger" key causing the explorer.exe to stop functioning upon execution.  Once I deleted the debugger key, everything started functioning.

NOTE: this is a registry fix so BACKUP before you attempt to make this change!

To fix this issue you will need to make a quick change to the registry.

1. Start run command prompt: Regedit
2. Go to registry area: HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Image Execution Options\
3. Find the Key: Debugger and delete this key by right clicking over the Debugger key and click Delete.
4. Now if you execute the explorer.exe from the windows folder everything will work fine.

If you are new to Regedit I would highly suggest that you backup the registry before you perform this operation.

Later, I have also discovered later that this was the cause of a virus and to ensure this virus was totally removed you should perform these functions after the restore has been fixed.

1. Temporarily Disable System Restore
2. Update the virus definitions
3. Reboot computer into SafeMode [F8 Key on Bootup]
4. Run a full system scan and clean/delete all infected file(s)
5. Check the HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Image Execution Options\ area and remove all entries.
6. Reboot the computer and re-enable system restore.
7. As an added precaution I also removed all prior system restores.