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

Question

Lately, I've been having this problem where Windows was informing me that a file did not exist. For example, if I were to open up my-image.png from explorer, it would tell me that it wasn't found. Now, Picasa Photo Viewer had taken over the extensions, which is what I wanted when I installed it. So, I went to Picasa's Program Files Directory, and tried opening the viewer manually. This time, I was told that the app could not be found, even though I'd just double-clicked it.

Over time, more EXE files started doing it. I found that if I rename the EXE, it works. But the second I change it back, it "can't find" it again.

I don't have any viruses on my PC, everything else is performing fantastically.

Edit - This is happening with RAD Studio now as well.

Here's a snapshot of the error with bds.exe selected:

Edit 2 - Also, I have checked the exefile and .exe associations in the registry, and those are fine (set correctly).

It's just weird that most apps open, but BDS does not. Command line can't open it either.

Answer 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.