I tried to install Visual Studio Beta 2 from an ISO today using the Virtual CD Rom tool. This mounted the ISO fine as drive Z: but when I ran the setup.exe I got an error that it could not load the SITSetup.dll, even though this was in the ISO.

I copied the contents of the ISO to my physical disk and reran the setup and all was OK, so the tip is mounted ISO don’t always work as you expect.