Basically, I'm looking for a solution similar to the ones mentioned in a similar (but Linux-focussed thread) located here so that I can deny access to blacklisted IPs. I am specifically focussed on trashy form submissions to a number of publicly available websites that I host whose clients don't want CAPTCHAs. Almost every IP I've traced a bad submission to is on the various blacklists I've checked, so I anticipate knocking out the vast majority of my problems simply by denying these IPs.
There is an installer for Vista/Windows 7 64-bit machines mentioned on the Peerblock downloads page, but that is a little disconcerting for me for 2 reasons: 1) I would feel better if it mentioned Windows Server 2008 explicitly and 2) this leads me to believe that the software's intended use is for personal machines and I need a server-grade solution.
Anybody got software-based alternatives to recommend ... or have experience with these running on 2008 64-bit boxes?
Note: I realize that a hardware firewall is a better solution, but I have an immediate need and a cost crunch on my hands.
Thanks in advance.