I am having the same problem. I was doing an install of the host on a test box so I could generate my .Reg file and 13 didn't uninstall. So I uninstalled 13 from the control panel and then then tried to uninstall 14 as well, but it would not uninstall. It gives me a 1603 error. I tried the MSIEXEC.exe method and added a log which is where I got the error. A little help would be great. I don't want to have to reimage the box and start over if I don't have to. We are a corporate license. and this is version 14.1.9025 (custom host).