So long as you don't throw the data in a folder in My Documents, I'm fine with wherever you decide to put it. Some of Microsoft's games have stored data there in the past, which I find to be utterly asinine.
In principle, though, I know I'm a Windows-only n00b, but I'm more inclined to agree with CP on this one. I just don't see how having to switch accounts to perform system-critical tasks is anything more than an annoyance. Like miskat, I'm the only person who uses my computer, and that's the way it'll be until I get rid of the thing (which is hopefully sooner rather than later, but that's another story). Having a separate Administrator account to do things like install programs or change certain settings just seems needlessly inefficient. For instance, my family has Norton Internet Security (and yes, I know how vile a piece of software it is, but at least it does what they need it to do), and I have my brother, myself, and my parents set up as administrators, in case we need to tweak it to perform a certain function. I know I'm probably violating at least ten statutes of safe computing in doing so (especially in that I don't have them password-protected...at least I managed to do that on my own machine), but sometimes you can't fight convenience. As far as I'm concerned, if I make a change to a system file that screws everything up, then I was fooling around with something I shouldn't have been with my current level of knowledge, and I deserve the consequences.