I have a Windows XP Pro installation. We are upgrading to Windows Vista Home Basic. I tried to install the upgrade from booting the DVD and was told that it had to start from in the current windows. That is bad because often we simply upgrade machines that have OS problems and that always fixed the problem. Now it appears that can not be done? Or can it? Anyway, I start the existing OS and load the DVD. When it runs it comes back with a flag 0x45A saying the winsetup.dll is missing. Indeed it is not. The DVD works fine on another machine. (just to check). I searched the DVD and the file is on the DVD. I am at a loss what's going on. I even copied the file to the windows/system32 directory and verified it's there. That is in the path. It still returns the flag?