Vista received well-deserved criticism for bringing few noteworthy new features in its train when it arrived to take over from Windows XP. In contrast, Windows 7 offers plenty of new stuff to like. Fortunately, you can add many of these features to your Vista or XP machine by using downloads and Web services.
What it is: Windows Vista can already stream music, videos, and other content between networked PCs in your house, but Windows 7 goes a step farther: It makes your media available over the Internet. By taking advantage of that option, you can watch a recorded TV show at a friend's house, say, or stream your mammoth music library to your storage-strapped netbook.
How to get it: The new OS's media-sharing system has at least one major drawback: It requires Windows 7 to be running at both ends. Third-party alternatives, on the other hand, usually have no problem with different versions of Windows--or even with different platforms (Mac and Linux). Simplify Media, for example, can stream music files saved in various formats from your desktop music library (or from any friends whom you care to invite) to any other PC. An associated iPhone app (Simplify Music 2.0) handles streaming on the run. Both the software and the service are free.
Another possibility is Orb, which streams music, videos, photos, and--if your PC has a TV tuner--live or recorded TV shows. Using Orb can even help you share documents.
What it is: An ISO image is a single file that contains the archived contents of a CD or DVD. Windows 7 enables you to burn ISO images to optical media, so you can crank out your own bootable discs. (Microsoft distributed the Windows 7 Release Candidate as an ISO file, which users had to burn to a DVD for installation on their PCs. Ironically, anyone working on a Windows XP or Vista system needed to use third-party software to handle the job.)
How to get it: Several free utilities can burn ISO images from Windows XP or Vista PCs (and with more options than you'll get in Windows 7). I'm partial to ISO Recorder, but you may also want to try Active ISO Burner or IsoBuster.
Improved Windows Paint
What it is: Windows' ancient, bare-bones graphics program, Paint, finally gets a thorough remodeling in Windows 7, complete with a jazzy new Ribbon interface (very similar to the one that people either love or hate in Office 2007), additional brush and shape choices, and various small but meaningful tweaks.
How to get it: Though you can't obtain Windows 7 Paint in Vista or XP, several similar Vista- and XP-compatible programs are even better. Regular PC World readers have seen us talk frequently of the open-source GIMP and the freeware Paint.Net, two Photoshop-caliber image editors. Either of these apps can run circles around Win 7's Paint, and neither will cost you a dime.