Having spent over 20 hours trying to install zass 9.1.507, I finally had to give up. I was able to get 9.1.008 to install once but I removed it in hope of installing the newer version. I tried everything form spending about 3 hours with tech support chat, changing permissions, doing all the cleans,cpes, editing the registry, everything that has been suggested to do but the install always hangs on the zlquarantine file. However I believe it is an issue with the files which are installed next which launch the antivirus aspect of the install. I do not know what serendipity there was when the 9.1.008 installed. I only installed in safe mode with networking. My system is an xp pro version 2002 with sp3.Other than this install I have not had any other problems with the pc. One time during an attempted install of 9.1.507 I was unable to boot and had to use a 3rd party cd to do a partial restore. Another time I kept getting the BSOD early in the boot. Had to restore that also. I am very unhappy and frustrated, and the tech support simply does not what to do- they have no solution. Lastly, I cannot even reinstall a previous version from the 7.0 series. At present I am doing a system restore and will see if I get any za back at all.