Originally Posted by nekrosoft13
so if OS gets screwed up
Never happened to me since Windows NT 3.51 (1996). And I see no reason why OS should "get screwed" for IT knowledgable user, if it's not Windows 95/98 (or some untested Linux distro)...
But I understand your concern. I have heard there were people regularly reinstalling Windows. I prefer to install it and use it till new OS comes out
And about backups - you have to make (preferably daily) backups of your data, which are usually much more valuable. I see no reason for OS to be excluded from this backup, as it is like 2% of total backup volume.