Under dual-boot conditions, it is most advantageous to have your most robust operating system set up as boot priority 1. This gets you on the web fast and safe, and keeps your more fragile system in reserve for windows-specific tasks only. Acer and Asus offer a Linux "quick-start" option on many of their Windows 7 equipped laptops, for just this purpose.
In addition, the EXT3 or EXT4 file system in the Linux partition is very efficient and never requires de-fragging; as much of your data as possible should be stored here, safely and securely.
Personally, I recommend only one O/S per drive. I use Linux exclusively, now(Puredyne - http://puredyne.org/), but have a small hard drive with XP loaded, to run Windows-dependent software, if necessary.


just looking for clues...
Oren.
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