Beta installed no probs but uninstalling 3.5 left remnants which I don't like. Uninstalled Beta,deleted reg entries and files and reinstalled beta. Reverted to free version which is no big deal but ZAP keeps flagging the beta on opening as wanting to autostart with windows which is not available in the free version. Finally set ZAP to deny and remember setting. Other than that,about the same scanning speed as 3.5,very nice gui and icon.Yep,it's a keeper at this stage.