You know Butterfly I disagree. If you compare like with like installing a new operating system onto a system then with windows your going to have some problems as well with drivers and connecting to a network etc. If your user is a complete newbie as well then they are always going to ask questions.
I was offered a free copy of Vista and turned it down because I just didn't think it was reliable enough. I was a windows programmer when I worked in the UK and everyone of the guys I worked with hates Vista. XP is OK but for browsing, wp, spread sheets and web developement Linux is better. The only problem I have with it is it does not run Adobe photoshop / Illustrator. I don't care what FF says The Gimp is a pile of arse.
Overall these days I think your better off in Linux, if your starting from scratch, or have a good understanding of computer science.
If you are an ordinary computer user and you don't like computers that much and have always used windows then maybe stick with it but you may be going up a dead end street.