Windows cannot find '?.exe' - some apps only

Solution 1:

Check the following registry key:

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

On a 64-bit system there is a second copy of this key for 32-bit applications:

HKEY_LOCAL_MACHINE\Software\Wow6432Node\Microsoft\Windows NT\CurrentVersion\Image File Execution Options

This key can be used to launch a debugger automatically when the specified application is started (see also this and this for more information). However, if the Debugger value in a subkey of this key points to a nonexistent file, any attempts to start the EXE file with the same name as the subkey will fail with a “file not found” error.

If you see any subkeys which should not be there, delete them (after making a backup of the registry key contents). In a clean Windows 7 installation there are two subkeys under this key:

• DllNXOptions — contains a list of DLLs that are known to be incompatible with DEP;
• IEInstal.exe — contains ExecuteOptions=0x00000000 (this value does not seem to be documented).

Some malware may use this key to disable important system components (e.g., explorer.exe) and antimalware programs, and sometimes antimalware programs remove the malware executable files, but leave registry keys under Image File Execution Options pointing to the location of those files, which will result in the errors you are seeing.