The just-released Beta 1 version of Windows 7 is a solid, fast-performing, stable operating system that appears to be just about fully baked and ready for prime time. It is much further along than Windows Vista was during its initial beta phase, and it appears to be feature-complete. Based on the stability and speed of this beta, don't be surprised if Microsoft Corp. releases Windows 7 before 2010 rolls around.

The new, powered-up task bar makes an appearance for the first time in this beta, and it proves to be something of a mixed bag. As I'll explain later in this review, the task bar makes it much easier to manage and switch between open windows and applications, but it also mixes icons for launching applications with icons for managing open windows.

Note that this review covers only the features that made their debut with Beta 1 of Windows 7. For an overall review of all of Windows 7, see "Windows 7 in-depth review and video: This time Microsoft gets it right."

The new Windows task bar

The task bar, new in this beta, will no doubt be the most controversial new feature introduced in Windows 7. Gone is Quick Launch bar for launching applications that used to live at the left side of the task bar. Instead, large icons across the task bar are now used to launch applications.

By default, Internet Explorer , Windows Explorer and Windows Media Player all have icons in the task bar. You can, however, add an icon for launching any application to the task bar by dragging the program's icon to it, for example, from the Most Recently Used list on the Start menu.

Those icons do double duty because they also manage your open windows. For example, if you've already launched Internet Explorer, and you have three tabs open to three different Web sites, the Internet Explorer icon changes subtly to show three icons stacked on one another, as shown in the image above, indicating that you have three tabs open.

Hover your mouse over the stacked icon, and you'll see all three open tabs as thumbnails just across the top of the task bar. Hover your mouse over any of the thumbnails, and your entire desktop is taken up by that open window. Hover it over another thumbnail, and the desktop is taken up by that one. Click any of the thumbnails or open windows, and you'll go straight to that window.