i have been getting the eroor msg explorer.exe application not found when trying to click the control panel icon it also seems to have removed al the system tools like notpad calculator the lot!
and windows itself is running fine? would strike me as odd that you even have a control panel icon to click on if explorer was gone ..
try booting in safe mode and see if it works there - in case you have some malware running that tries to hide stuff from you.
Alternatively try using cmd and check if explorer exists in windows
( dir %systemroot%\explorer.exe )