As in the Windows 7 Disk Policy Options:
[x] Enable Write Caching on the device
[ ] Turn off Windows write-cache buffer flushing on the device
Is the first the cache on the physical disk, and the second the windows cache?
(I've googled, but didn't find a clear answer).
Best Answer
See "more information" section from http://support.microsoft.com/kb/332023:
Write caching improves disk performance greatly, so leave it on for internal hard drives.
Windows turns write caching Off for flash drives and other usb hard drives by default, normally you do not have to ever modify these settings, Windows takes care of it for you.