Microsoft is selling Windows 7 home Premium upgrades for US$49 (half of its suggested $119 retail price) until July 11. Microsoft has limited how many copies people can buy, but I'm certain that some enterprising people will find their way around it and stock up. I anticipate a surge of eBay sales after Oct. 22, when the OS' cost goes back up to its full price. Update: There is a 25 PC cap.