Carl Farrington said:
Open up regedit (if you can), and navigate to:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File
Execution Options\cmd.exe
with cmd.exe highlighed, can you tell me what is shown on the right?
In fact, cmd.exe shouldn't even be there under normal circumstances, so if
it is there then the problem is what I suspected. Something (virus/malware
typically) hijacked cmd.exe. That something is now gone but the hijack is
still in place and needs to be removed.
Windows would never otherwise report "cannot file <full pathname to
executable>" when you just gave it a filename (no path), and Vista certainly
would just start searching.
The hijack is through a value named Debugger whose data (an executable
filename) is run instead of the original file (cmd.exe in this case), with
the original file passed as a parameter to the debugger.
You should just delete the cmd.exe registry key (the folder icon on the left
within regedit, that you highlighted before).