Up to 55% off: Windows Anytime Upgrade
Who's eligible: Anyone running Windows 7 Starter, Home Basic, Home Premium, or Professional
If you custom-build a new PC, you can choose the exact Windows 7 edition you want on it. OEMs get the best pricing, so this is usually your best option. But if you purchase a preconfigured PC from an online or local retailer, you get whatever edition of Windows they chose to install on it, typically Windows 7 Home Premium for consumer PCs. Outside of the U.S., Western Europe, and other developed markets, you might get Home Basic, and on a netbook you can get the wimpy Starter edition.
Purchasing a full retail upgrade is one option, but the Anytime Upgrade option can be much cheaper. For instance, a retail upgrade of Windows 7 Professional costs $199.99. If you have a PC with Windows 7 Home Premium already installed on it, you can buy the Anytime Upgrade option for $89.95 direct from Microsoft. Likewise, you can go from Windows 7 Home Premium to Ultimate for $139.95, which is a considerable savings over the $219.99 retail upgrade price for Ultimate. (The full price list is here at the Microsoft Store.) Online retailers like Newegg.com offer the same deal for a discount of a few bucks, although you have to wait for a physical box to be shipped.
Up to 58% Off: Windows 7 Home Premium Upgrade Family Pack
Expires: "Limited time offer" with no specific expiration date [Update: as of December 4, 2009, the Family Pack appears to be sold out in the United States] [Update 2: Microsoft repeated this "limited time" offer in Fall 2010; it could expire as soon as December 31, 2010. See this post for details.]
Who's eligible: Any multi-PC household (international)
If you have two or more PCs in your home and you want to upgrade them to Windows 7, this deal is for you. This package is only available in a physical box and (according to Microsoft) only for a limited time. It includes two DVDs: one copy each of the 32-bit and 64-bit Windows 7 Home Premium upgrade installation media. You get a single product key that can be activated on up to three different PCs.
In the United States, I found the Family Pack at the Microsoft Store for $150, but you should be able to pick it up elsewhere for a discount of at least $10. Even if you only use two of the licenses and thus pay an average of $75 apiece, this is a big savings over two single upgrade copies at $120 each. If you use all three upgrades, the cost per machine is $50 or less.
According to Microsoft, this offer is also available in Japan, Canada, Germany, the UK, France, the Netherlands, Switzerland, Austria, Ireland, Luxembourg, and Sweden.
The license says you can install Family Pack upgrades on up to three PCs in the same household, for use by residents of that household. When I asked Microsoft whether it was OK to use this license in a home business, I was told, officially, "There is no restriction around use of a license for business purposes conducted within the home," although naturally they recommended Windows 7 Professional for those situations.
Nothing in the license prevents you from mixing and matching the 32-bit and 64-bit versions on up to three PCs in your household. But no, you can't share licenses with your neighbor or your cousin in Peoria.
Up to 50% Off: Buy a new PC, upgrade your old PC for half off
Expires: [Update: This offer expired on January 2, 2010]
Who's eligible: Anyone who buys a new PC with Windows 7 from a participating retailer
Microsoft has publicized this deal on its website, but retailers seem a little shy about promoting it. When you buy a new desktop PC or laptop with Windows 7 included, you can buy a second upgrade copy of Windows 7 for use with another PC at a discount. The estimated price for a copy of Windows 7 Home Premium is $49.99, Windows 7 Professional is $99.99, and Windows 7 Ultimate is $119.99.
According to Microsoft, the following merchants in the United States are participating: Fry's, Newegg.com, Staples, Office Depot, Costco, Best Buy, Radio Shack, Amazon, Tiger Direct, Walmart, Buy.com, and The Microsoft Store.
If you go to Newegg, you'll find the offer available as a Combo Deal with individual PCs. So, for example, if you buy a Toshiba Qosmio X505-Q830 you can pick up a second boxed retail upgrade of Windows 7 for $70-100 off. I didn't see any mention of the offer in this week's local ad for Best Buy. Maybe a salesman would offer me this deal if I shopped at a local store.
Amazon.com offered the deal on this page, but I didn't get any clue or pointer to this offer when I added a new PC to my shopping cart, and the promotional discount wasn't applied to my order until I was ready to check out.
If you're planning to buy a new PC anyway, this deal is worth it, but you might have to be persistent to get it.