Some of the improvements in Windows 7 aren’t apparent without digging around a bit. One of the improvements is in the disk defragmenter. The interface has been redesigned and by default defragmentation jobs are scheduled weekly at 1:00 AM on new installs. Defragmentation helps keep your files in order and can greatly improve your performance, especially on large drives.
One of the cool features in Windows 7 is that it is smart enough to know not to defragment solid-state or USB drives to help preserve their life. A lot of people are unaware that solid-state drives (like that USB stick you store your files on) have a limited number of read/write cycles to them!
It’s just one more way Windows 7 is helping make your digital life a little bit easier.
Windows 7 in 77 Seconds – Disk Defragmentation