Dude,
Bad news, Arcserve 6.5 will not run on Windows 2000. There used to be a patch that would allow 6.61 to run on Win 2000 but I don't see it available on Computer Associates site any more. I believe (someone correct me if I'm wrong) that you must upgrade to Arcserve 2000 if you want to run on windows 2000. However on the plus side you should be able to buy an upgrade version.