You should also change the Save directory to the users home directory. This changes with Vista so you want to do some reading up on Microsoft's official forums.
You honestly wouldn't believe just how much reading up i've done on Windows Vista.
I am currently aware of issues with Windows Vista not allowing the program to decompress its files (which is used in auto update and the first time you launch it after installing). I'm looking into possible solutions to this.
I do know
exactly what is going wrong in instances where install seems to be incomplete under Vista.
At present, the solution is for the user to modify the program's shortcut to let it run as an administrator.I'm also aware that the save folder wants moving to the user's home folder, and it will be at some point in the future.
As far as I know, neither of these issues affect Windows XP.
I'd also like to add that it's not SuckerPunch's installer, so the blame for any issues relating to its performance lies with me. - If it were his, it might work better.