It used to be that we'd always recommend partitioning a large capacity hard drive into two separate chunks, one for the operating system and the other for storing files. The reason for this is that you could generally expect a Windows install to go bad at some point, whether due to a virus outbreak or just too much accumulated cruft. By storing your important work documents, family photos, and everyone else on a separate partition, you could wipe out your main OS partition and start fresh with a new install of Windows without losing your files. It looks like Windows 8 will come with a built-in feature that borrows on this philosophy.
Originating from win7china.com, a leaked image of Windows 8 shows a reset button taking residence just underneath the System Restore option. The reset option is designed to restore Windows 8 back to original factory settings with the following description:
"Remove all programs you've installed and restore default Windows settings. You can choose to keep user accounts and personal files."
The ability to keep personal files intact will come as a boon to those who don't want to partition large drives, so long as you trust that nothing goes wrong in the process. Of course, if something does go wrong, it's not like you didn't back up your files beforehand. You do practice frequent backups, right?
On a related note, this feature could make fixing family and friends' badly infected PCs a snap.