Yes, it would be an older Vista installation. If you're sure you got all your documents and saved games out of there, then it's safe to delete.. I was surprised to see that Vista throws so much data into the Windows.old folder, including every user's documents but at least it's a lot more organized. When you can buy 1TB of hard drive space for 70 bucks, I don't see any rush to delete my own Windows.old folder, in fact, I've got several.. I guess when I start getting closer to using around 10% of my 4 teras of hard drive space, I'll think about cleaning house..