I have 64-bit Windows XP and I installed 3.0 server and of course it doesn't work due to lack of a mirror driver. I then uninstalled it and installed 2.1 again. However, I can no longer connect to the computer using the 2.1 viewer, it says "Incorrect version of server."

How can I get 2.1 working again without reinstalling windows (which I will not do)?