Both analyst firms said PC shipments shrank in the U.S., with Gartner pegging a decline in PC shipments at 5.7 percent compared to the same time in 2011. IDC's forecast was even more bleak, with the company saying PC shipments in the U.S. shrank by 10.6 percent. (IDC and PCWorld are both owned by International Data Group).

Microsoft is offering anyone who buys a new PC before January 31, 2013 a . Despite that deal, many prospective buyers appear content to wait for hardware designed for the new OS, according to IDC. That's not a huge surprise, considering past Windows upgrade headaches such as , and . 

The dramatic shift in user interface and basic functions in Windows 8 compared to Windows 7 may also be inspiring people to wait for new hardware in the fall. Unlike Windows 7, the newest version of Windows is designed for touch from the start, with a new Metro-style UI similar to Windows Phone.

The traditional desktop still exists in Windows 8, but the first thing you see when you boot into Windows 8 is the new Metro Start screen featuring live tiles showing information such as social networking updates, calendar appointments, weather, news headlines, and e-mail. With touch playing such a central role, new laptop-tablet hybrids are expected to accompany the Windows 8 launch. New touchpad gestures designed for Windows 8 will also be included in new PCs later this year.