Microsoft Friday initiated its half- price promotion - to run in the US and Canada till July 11, and in Japan till Jul 5 - for its forthcoming Windows 7 upgrades for Home Premium and Professional. Pre-orders for the upgrades will begin in UK, France and Germany from July 15.

The upgrades are being made available for a cut-rate of $49.99 for Home Premium and $99.99 for Professional - the post-promotion retail price of the two upgrades will be $119.99 and $199.99 respectively.

Both the discounted upgrades would be available for the users of Windows XP and Windows Vista. A clean install will be required by Windows XP users, as well as those moving from a 32-bit version of Windows to a 64-bit one.

The pre-order deal for the upgrades of Windows 7 is available only online. It can be purchased in the US from Amazon, Best Buy, Wal-Mart, Costco, Fry's Electronics, Microsoft Store, Office Max, Sam's Club, Staples, Tiger Direct, NewEgg; in Canada, through Staples, Best Buy, London Drugs, Future Shop, Amazon, and the Source; in Japan, through Amazon, Yodobashi Camera, Bic Camera, and Yamada Denki.

According to the sales rankings by the company, Amazon shoppers are showing interest in the currently-discounted upgrades; with Home Premium upgrade turning out to be the top seller in the Amazon software segment, followed by the Professional upgrade.