Since the company hasn't been straight about what that limit is, if you know you want Windows 7, get it sooner rather than later. Actually, 'until July 11' might not be accurate, as Microsoft has made it clear with repeated references to 'until supplies last' that it may cut short the deal.

and Canada, and Windows 7 Professional Upgrade for $99.99. Microsoft's selling Windows 7 Home Premium Upgrade for $49.99 until July 11 in the U.S. What's the cheapest price for Windows 7? Unless you're buying a new PC - more on that later - the best bet now is to reserve your copy at Microsoft's online store or one of the retailers participating in the discount offer.

Your questions on cost, our answers on prices follow.