Can't install CIS Beta 8

After uninstalling CIS 7 I tried to install the new beta but Win8.1 crashed two times during installing - blue screen with registry error message.

Post your system specifications

Try this: Comodo Forum

Unfortunately the unofficial removal tools present in the mentioned topic are getting old to remove the traces of the newest CIS versions… Third Party programs like Revo Uninstaller and Iobit Uninstaller are also not solving the problem. I believe that Comodo should really consider developing a official removal/uninstaller tool, updated each time a new CIS version is released, to remove all traces… All other companys do this. Why can’t Comodo?

Thank you for replies. Finally I reinstalled my win8 and CIS8 Beta works fine.