I have a problem on win XP where every command I run including cmd and msconfig do not run but open as text files for editing. This happened after I manually tried removing the New Folder.exe virus due to the failure of my antivirus to deal with it.
I cannot run cmd unless I go to the exe itself and select the "run as" option from the right click menu. I have tried the properties with no avail. It must be a registry error but I am not sure what entry needs fixing.