Activestate has a PPM for Windows, it just fails some tests. That's usually not a huge problem, so long as you understand which tests are failing.
Oracle bought Sleepycat and they're releasing Berkley DB as an MSI file. I believe MSI files can be installed silently if you figure out the right options. That might fit what you're trying to do. I can't pull up the page right now, but do a search on Oracle's website and you'll find the download page easily enough.