On my system, I already had the MinGW 32-bit compiler installed.
But from Twilight Dragon Media's TDM-GCC package, rather than MinGW directly.
Blimp would throw an error when I tried the emulator (F5), saying it couldn't find the compiler.
Before I overhauled my system, I tried this simple test:
Renamed the compiler directory from C:\TDM-GCC-32 to C:\MINGW
Although I haven't tested extensively, that seems to have done the trick.
I was able to enter emulation mode and operate the OSD project on my PC.
I thought I would post this in case someone else is using the TDM distribution.