Windows Vista license sales after one month of availability have already exceeded the total of Windows XP license sales in the earlier product's first two months of availability.

"We are encouraged to see such a positive consumer response to Windows Vista right out of the gate," said Bill Veghte, corporate vice president of the Windows Business Group at Microsoft. "While it's very early in the product lifecycle, we are setting a foundation for Windows Vista to become the fastest-adopted version of Windows ever. Working with our partners, we are helping our customers leverage new tools and programs to accelerate the transition and provide a great user experience."

The more than 20 million copies shipped represent Windows Vista licenses sold to PC manufacturers, copies of upgrades and the full packaged product sold to retailers and upgrades ordered through the Windows Vista Express Upgrade program from January 30 to February 28.