Changing Vista's owner

I received my dad's laptop the other day, and it has Vista installed on it. Naturally, when we were doing the initial setup a few months ago the name was set to my dad's name. Now I want to change it to mine.

I've already changed the account name (the administrator one) to mine, which I assumed would've been enough.

I notice that whenever I browse to something like C:/Documents and Settings/User it sometimes uses my dad's name instead of the name I set for the profile. If I go do some other stuff or reboot, then it'll start showing up as my name (sometimes). It goes back and forth like this and I have no clue how to fix it. It's bothersome because, on occasion, I have no clue if I'm putting stuff in the right folders or whatever.

Anyone have any ideas on how to fix this?

Jam it back in, in the dark.

Because I don't want two accounts and that doesn't really solve the problem, just sidestep it.

Unless you're saying there's no fix, in which case I guess I'm resigned to it.

There's nowhere I can't reach.