PeerBlock is a type of program known as an "IP Blocker". IP-addresses are used to identify a computer whenever it connects to the internet. PeerBlock monitors each connection your computer tries to make with another one - and each connection other computers try to make with you - and then compares the other computer's IP address against a list of "known bad" IP addresses to see whether it should let this connection go through or not. Should work great on XP, Vista, 7, and 8+ (plus server variants), both 32- and 64-bit versions.
Download | 1.2 (r693)
Download | Portable