[BrianBruce]

Have you tried running the installer as an administrator? right click the icon and "run as administrator" is by the top. Sometimes older programs confuse the os and it defaults to "insufficient privledges".

If you want an account that UAC does not ask for privledges, you could enable the built-in administrator account.
right-click computer and click manage
expand local users and groups
click users
double click administrator
clear the disabled checkbox
click ok
right-click administrator
click "set password"
click ok then enter a password

This account bypasses uac and should give you any access you need.
Hope this helps