Well, here is the rub. If you run Microsoft, and the dual partition, C:\ for system, D:\ for files and user folders, when MS crashes and you restore, or re-install, it will format, and totally wipe the entire drive!
Reason #345 that I don't run Microsoft 'virus-Magnet'.
I have more than one partition, on more than one drive in each of my major 10 networked systems. But, I run the 50X faster, virus proof, Linux, just like Microsoft.com, Hotmail.com, and MSN.com does, on their 45,000 computers.
I run http://pclinuxos.com
The EXT3 filesystem is very secure, and self checking, and, with the topography it mandates, writing out from the center of he drive, it accesses faster, and it means no fragmentation can ever occur.
Also, Linux is totally virus proof, as are all the 'Nix's. 78% of all Internet servers, the Fortune 1,000, and all the charities and Public and private schools run Linux, BSD(Mac OS X also is BSD), Solaris.
I saw that all the November PC magazines on the newsstands are hosting Tux the Penguin, mascot of GNU/Linux, on their front covers, because the tipping point was passed some time ago, as 165 world governments and 4500 regional governments, have also embraced the secure, safe OS.
Something really cool is that Linux offers RAID or LVM upon boot up for the install. Logical Volume Management treats all drives you identify on the network as just one big drive, and then, it can also 'stripe' the data, so multiple copies span several physical drives, for fast, safe, restoration!