Microsoft is expected to unveil an upgrade program for Windows 7 that will likely let you get the operating system for free or with a discount if you've recently purchased a Vista-based PC that meets certain conditions. So what are those conditions? That's not yet clear. Microsoft has confirmed the program will be called "Windows Upgrade Option."

Early speculation suggests that it may mirror the Vista Express Upgrade program, which provided free or discounted upgrades for users who had bought XP-based systems in the months leading up to Vista's release.

That program didn't exactly run smoothly, however: At the time, PC World expressed concern about hidden costs that were associated with the Vista upgrade, and many consumers complained of delays and other issues in getting their upgrade requests processed.