Keyloggers aren't as big a problem as them connecting to the internet to send the logs to whatever So while you search for a detection tool, get a good outgoing firewall ASAP. This may also incidentally detect your keylogger when it tries to connect to the net.

There are several free and paid ones out there though the only one I know that's free and nice and works well with win7 64 is COMODO personal firewall.