Mom would like to get our windows replaced, I think, but they're pretty good. About 15 years old, but they still work properly...
It was very funny, though, when someone would call to try to sell us vinyl siding... Mom would just say, "Um, we live in a log home," and they'd hang up so fast...
Our house was built 16 yrs. ago, but the windows were not very good quality. That's why we're going ahead and replacing the existing ones so they'll be better quality and will match the ones in the addition.