I recently installed latest binaries for Windows on Windows 7. I find that Environment Variables are case-sensitive - a problem which wreaks havoc with Unicon: e.g., getenv("PATH") fails because the environment variable on my Windows 7 machine has been set to "Path" - accordingly getenv("Path") succeeds.
There is a lot of blather about the issue on the Net, and mention that is is "fixed" in .NET 4.0 - but nothing generally for Windows 7.