Advised not to de-frag C: drive because of volume shadow copy

I haven't manually defragmented my drives ever since I switched from XP to Vista (~about 2 years ago).
This thread made me check it out again. When I learned, that Windows 7 runs an automated defragment once a week I got curious/investigative. If you enter "disk defragmenter" into the search dialog, you'll get info about the last run. It showed all my drives had been processed sucessfully so I just leave it alone to do its thing and enjoy Microsoft's best OS so far
Thanks to all here who helped giving me their opinion on that matter.
BTW: since the last run my C-drive fragmented by 5%. To see how long it would take I ran the program manually..it took less than 20 minutes.



-DG

When you defrag, the computer moves all the files, and parts of files, around on the physical disk surface, to optimize their layout and reduce seek times. When this happens, VSS (Volume shadow copy) interprets each movement as a change to a file, and tries to record the previous version. Obviously,that will make your hard disk fill up extremely rapidly, which is why it’s a bad idea to use a defragmenter if VSS is running.

If you dont want to use the inbuilt win7 defrag, then use something that is compatible with VSS. I believe the recent versions of Auslogics and Diskeeper are VSS compatible.