I hesitate to say anything that contradicts what BrowserUk posts since I usually find out that I'm wrong. However, I'll share what I have been able to do.

In both 32-bit and 64-bit Windows 7, here's what I have been able to successfully do with 32-bit ActivePerl 5.12. Launch the PPM in GUI mode and install mingw (PPM will also install dmake). That installs without complaint. Considering that aftewards on both 32-bit and 64-bit Windows 7 I was able to install modules via the cpan utility (e.g.: cpan install PAR::Packer) which seems to invoke dmake, I'm assuming that mingw and dmake were installed and were working properly.

However, based on the link in BrowserUk's post, I'm guessing that I might eventually hit a problem with doing the above on a 64-bit Windows with 32-bit ActivePerl. Anyways, just wanted to share what I have "successfully" been able to do.