Once the Upgrade Advisor is installed you can run the scan to generate a report of software and hardware issues that should be resolved before you attempt to upgrade to Vista.
Note: on one of my VMWare test pc’s I had to download MSXML 6 in order to install the Upgrade Advisor. The first step I took was to download and install the Vista Upgrade Advisor, to test for software and hardware compatibility. My licenses for Windows Vista Business Edition arrived last week and so I thought I would document the process I followed for upgrading from Windows XP Professional.