VMware’s ThinApp 4.0 product has added a new feature to the previous versions of ThinStall called AppSync. Among other things, AppSync allows for administrators to build ThinApp packages that periodically check in to a web site to see if there is an update.
Using VMware’s ThinApp 4.0 AppSync feature with a Microsoft Web Server can require additional configuration to the web server as, by default, IIS 6.0 does not allow access to any file with an unknown extension.
How do you set IIS 6.0 to allow download of files such as EXE’s or DAT’s. By default, Microsoft’s IIS 6.0 will not serve out any unknown extensions. This includes EXE and DAT. Therefore, when a user requests such file, whether it be via ThinApp or directly, IIS will reply back with a 404 status code. A look in the IIS log file will show the sub-status code of 3 meaning the complete status code is 404.3. This means that the MIME restrictions prevented the request.