Windows 7

I love Aero Snap (it's especially fantastic with two monitors). Just pull down on your browser's taskbar, and woosh! The window is no longer maximized. Holy crap! It gets even better if you're using a modern browser, which allows you to drag-and-drop individual tabs. Combine this with Aero Snap, and pretty soon you're flipping windows all over the place. Wooooooooooo! Want to see your desktop? No problem, just drag that maximized window out of the way. Sick of your stupid desktop? Drag the window back up. Maybe you want to see two windows at once-- no problem. Just flick one window to the left of your screen, and one to the right. Screw keyboard shortcuts, you have a MOUSE! With Aero Snap in Windows 7, window management is simply super special awesome.

Although Windows 7 does have (decent) backup capabilities it should not be tagged "backup".

Short guide to make this OS leightning-fast: disable useless services, disable visual styles, install xplorer2 for file management and bbClean shell.

I used the demo awhile back and its a great OS. I look forward to upgrading to it for my next computer

Unlike Vista, which only introduced pretty colors and pretty annoying UAC, Windows 7 is clearly better than its predecessor (though the bar may have been set a bit low). UAC can be toned down instead of just plain shut off, though I still prefer to turn it off completely. The new taskbar is a massive improvement of the traditional taskbar of the Windows OS. And there are lots of other cool stuff, too.

With Windows 7 you do not need a special defragmentation application as listed in (3):
One of the aspects that has evolved in Windows 7, compared with Windows Vista, involves the operating system's capabilities to glue back together disparate fragments of files that have become fragmented as a natural consequence of hard disk use. “The defragmentation engine and experience in Windows 7 has been revamped based on continuous and holistic analysis of impact on system responsiveness,” Rajeev Nagar and Matt Garson, both program managers on the Windows 7 File System feature team, revealed.
(1) http://news.softpedia.com/news/Windows-7-Defragmentation-Engine-the-Evolution-102941.shtml
(2) http://bit.ly/7EInfk
(3) http://alternativeto.net/SearchResult.aspx?profile=all&search=defrag%20defragmentation&category=desktop

Only One "System Image" with Windows 7 Backup-Function:
It looks in such a way, as if in each case only one (the latter) system image remains. Further past system images are always overwritten by the latter. If one wants to have the possibility of restoring the next to last or before-next to last "System Image" then one must use e.g. a specialized system backup software as "Macrium Reflect Free Edition" or "Acronis True Image Home":
http://alternativeto.net/desktop/macrium-reflect/
http://alternativeto.net/desktop/acronis-true-image/