Try uninstalling the card and then rebooting, let Vista find the drivers during the reboot or you coudl point it to the intel drivers after it asks for them.
Right click my computer and go to manage. click on device manager and find your network adapter, then right click again and uninstall. Reboot and see if Vista installs the correct driver or the latest intel one you have.
what i would do - and its a bit of a long ass process, but last time i had issues with a program like that i removed everything symantec from the pc, rebooted, went through the registry looking for any symantec keys, deleting them all, and doing one last reboot, then reinstalling, and that worked for me
i've tried that but as soon as i uninstall vista automatically discovers the card and installs drivers automatically. sometime they are the older versions which still doesn't fix the issue (version 10.6)
go to c:\windows\inf - look for oemxx.inf (xx being a number) read each one and find the one for the network card, and then del the file, uninstall the card and then re-install it - vista will not see it as you have wiped the file, then use the correct intel drivers