Yes, I was referring to Open Watcom. It's very possible that there are conflicts between that compiler and MS or MinGW. I just renamed 'make', but there could be other names in common. Perhaps I could try renaming the Watcom installed directory. But I do use that compiler frequently, so it's a bit of a hassle to kill it, even temporarily.
I did try using PPM to install Imager. That produced the same errors as before.
I was wrong in adding 'x86' to the machine spec. It is a 64-bit machine which, under Win7, can run either x86 (32-bit) or 64-bit code.