You know, I spent too many years reading Slashdot. I somehow got the impression that Windows did not have a good source of cryptographically strong pseudo-random numbers. While true for Windows 95 and Windows 98, this has not been true for years.
Microsoft Windows has had, since Windows 2000, a form of /dev/random/ called CryptGenRandom(). Indeed, it appears that MinGW/Msys have the required wincrypt.h header file for supporting this function.
I will have to, once I get the DNS resolution bugs fixed, set things up so Deadwood uses CryptGenRandom() for some of the entropy for random query IDs and ports, and not require a secret file.