I have gotten CVF 6.6c (full ide) to work in win7, 32bit. Of course, you have to answer the installation questions Yes or Continue. At that point the dfdev.exe will load--if it doesn't see next sentence. I had a problem with it crashing when a .dsw is loaded but fixed that by invoking the win7 Troubleshoot Compability -- right click on the shortcut to dfdev.exe -- and finally (after much experimentation) selecting win98 compatibility. Yes. Even though a strange messagebox pops up when a dsw is loaded, modules compile, link, and run as before. No, I haven't actually done any debug/trace so far.
If you have win7Pro or better and a compatible cpu and bios (with virtualization capabilities), you can download XP mode for win7. Although I haven't done this, it might enable running the IDE within the virtual machine. See http://www.microsoft.com/windows/virtual-pc/download.aspx.
The new Intel fortran is much better/newer, of course, and integrates beautifully into VS08, it doesn not have the source browser function of CVF6. That's a killer for large apps, so I keep both around.
The other thing is that I had CVF6 running on Vista32 and upgraded it to Win7 and it continued to run as before, no problems, no error messages.