I am trying to use a package called virtualenv for Python, which temporarily changes the PATH environment variable to add a certain directory and give convenient access to several executables. My problem is that this doesn't seem to work. The directory gets added to the start of the path as expected, and I can verify this by typing PATH at the prompt, but if I type the name of an exe in that directory, it doesn't run. If I navigate to that directory however, the app will run ok. It seems like Windows is ignoring the altered environment variable, perhaps using what was listed for PATH in the registry (eg. HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment\Path).
Does anybody know what could be causing this? I am running as an administrator on Windows 7.