Make a system restore point.
Download the drivers you need for the Intel Centrino Advanced-N 6235 and save them to your desktop.
Start, control panel, device manager, network adapters, right click on Intel Centrino Advanced-N 6235, left click uninstall. Tell it to remove the software and drivers.
Restart your computer.
When you log back in with an unrestricted user account, the new hardware wizard will try to install the adapter. It usually fails to install. Then install the drivers that you saved to your desktop.
Thanks for the helpful response.
Out of interest, is there a version of the driver from Intel that provides an add/remove programs entry in Windows control panel? Just because it can be useful to see at a glance which drivers are installed.