Program Compatibility Issue, cannot run

There is a calculator program that I've used forever up to XP-SP3. It's a small fast program that does not install; simply click and run each time. When I run it under Win7/64, I get the error dialogue box: "The version of this file is not compatible with the version of Windows you're running. Check your computer's system information to see whether you need an x86 or x64 version of the program..."

I've set the "compatibility for all users:" to:
Windows 95
and checked all five boxes starting with "Run in 256 colors", etc.

Nothing helps. Short of running the compatibility emulator, which is slow and sort of defeats the purpose of this quick little program, is there anything else I can try to get this to run?