The time of homebuilt machines appears to be fading since laptops are more common and you wouldn't want to let consumers deal with the issues of installing the OS as it comes from Microsoft.

Factor in that Microsoft has no apparent interest on making the install easier (just look at that driver disaster) and no software company could get this one right. Let's not speak that Vista would wipe out any effort you would put into creating such for XP.

-> So no. You'll have to create your own method to safeguard your files and more.

I do wonder how you backup. I read about partitions, but these are proving to be fragile during crashes. Where's the backup?