Windows Vista User Accounts OS Upgrade Question

I am seriously considering upgrading my OS. Probably wont be anytime soon but I would like to have this knowledge before I even consider doing this. I have read through all many of the threads regarding upgrading you phone and should not be do challenging. Since I have successfully flashed my xbox 360 shouldn�t be too difficult to update my bb OS.

My computer died a few months back and instead of getting my own laptop my wife decided to just get a really nice laptop and we would just share that.

Now after reading the threads on upgrading your OS, I see I will need to uninstall the current DM and install the leaked version. My concern is that since we share the laptop (both have Admin authority) I am pretty sure my wife will not want to upgrade her OS, so does anyone now if the user account profiles are separate since we are both admins. Meaning� if I delete and install a new DM on my user account profile will it affect my wife�s DM when she connects her bb?

Hopefully this makes sense and if there is already thread talking about this that I was unable to locate please point me in the right direction.

Thanks!