Step 1.
Download Vista Upgrade Advisor tool (more info) and run it.

Step 2.
You will see the “Welcome to the Windows Vista Upgrade Advisor Setup Wizard” (first page); click “Next”

Step 3.
read the license agreenent, select “I Agree” and click “Next”

Step 4.
after successful installation double-click the shortcut “Windows Vista Upgrade Advisor” tool will be “checking for updates”

Step 5.
now You see “Windows Vista Upgrade Advisor 1.0″ click “Start scan”

Step 6.
when scan is completed click “see Details”

Step 7.
You can choose edition name and see report details