It updates signatures daily, however, I have active: NOD32, AVG Anti-Spyware, Windows Defender and Comodo Firewall. I have an active license and scan weekly with Spy Sweeper and update and scan with Spyware Doctor with my work license. I browse 99% of the time sandboxed and never find any malware anyway. If you all believe that BOClean is a useful tool I'll keep it active, if not I'll uninstall it. Thank You!