Applying shims to standard Windows programs

While browsing for information about the Windows application compatibility shim engine, I found someone remarking that they had trouble applying shims to Notepad for demonstration purposes.

It is possible to shim standard Windows programs like Notepad, but an extra step is required. Like Windows DLLs, EXEs under System32 are excluded from hooking by the default inex policy. The shim definition must therefore have an INCLUDE directive for the executable, such as in this ShimDBC XML fragment:

<SHIM NAME="CustomShim" FILE="AcRes.dll" RUNTIME_PLATFORM="X86_ANY,AMD64">
    <INCLUDE MODULE="notepad.exe"/>
</SHIM>

The shim can then be applied as usual:

<APP NAME="Notepad">
    <EXE NAME="notepad.exe" RUNTIME_PLATFORM="AMD64" FILE_DESCRIPTION="Notepad">
        <SHIM NAME="CustomShim"/>
    </EXE>
</APP>

A few standard shims - specifically RedirectEXE, InjectDll, and TerminateExe - refuse to perform their function on system EXEs as determined by a function called ShimLib::IsSystemExeFromSelf, which appears to check whether the EXE file is owned by TrustedInstaller. That's not a concern for custom shims, though.