[RayChuang88]

The biggest problem up till now with Windows is the fact they have to maintain compatibility with not only older hardware, but older software, too. With Windows 7, Microsoft can officially ditch any pretense of Windows 95/98 compatibility, which means the entire OS can run in the true 32/64-bit flat memory mode for maximum stability. In true flat-memory mode, you can easily "protect" parts of memory to either 1) dedicate part of the memory for an application program and/or 2) make it easier to recover from program crashes. Indeed, with Windows Vista the display driver operates in true flat-memory mode, which allows for much more graceful recovery in case of display driver problems.

[Spktyr]

One problem - the lead MS developer for Windows 7 says that it won’t remove the 95/98/XP compatibility and that there *won’t* be an application sandbox for them.