Agreed. What I'm looking for is a study that quantifies some of what's going on here. How much actual performance is lost over time, how quickly does it happe

Agreed. What I'm looking for is a study that quantifies some of what's going on here. How much actual performance is lost over time, how quickly does it happen, and how are both of those factors perceived? The case of your in-laws sounds pretty typical, we've all heard it. Purchasing a new computer seems like a rather dramatic solution, but in their minds, fairly justified. I guess another question in my mind is the opportunity costs involved. Is the time spent restoring a computer to it's original state worth it when compared to simply purchasing a new machine? Of course, this varies with the ability to quickly re-install, so I'm considering this question mostly on the small end of the scale (home users, small businesses, where economies of scale haven't kicked in).