metro multitasking can only display two parallel applications only. It may have no effect if you are a computer novice user, but for computer experts this is very inconvenient time.
Metro UI and Aero UI (as in Windows 7), the two overlap. should be used only one, when Windows 8 will use the metro UI, it would be nice UI as in aero windows 7 removed.
no Alt + Tab functionality as in previous versions of Windows. sangatt difficult when it will switch between running applications.
Metro UI can work well on a tablet computer, but its function is reduced when using a PC.
Tiles. When Microsoft introduced the System Tray, the feature is referred to as critical that are designed to allow users easily access and view the status of a particular application will be expedited. But now in Windows 8, the System Tray instead be very disturbing. In Windows 8, Metro UI desktop will be widened latest System Tray. Each application will require the system tray. And a growing number of applications that are run, the system tray will bubble. Although Microsoft promised to provide a lightweight and easy to run, but if you use iTunes to stream, and there are many other applications that are run, we can imagine what will happen to our beloved tablet. Crashed!
There is no option to turn tiles into icons. The smallest size of the tiles, zoom is still too big. When we install a lot of applications will then screen the Metro will look chaotic.