I have that same exact wireless card, if you're not installing the drivers first, and then installing the card it will not work right.
So try this, (if you're not that is....)
Right click on "computer" click on "manage" now click on "device manager", scroll down the list to "network" and click on the + sign to open the sub menu. Right click on the entry for the card and click on "uninstall".
Now close any and all open windows and turn off the computer, remove the card from the computer.
Now restart the computer and install the drivers, make sure you get the latest updated version for Vista. Once the drivers are installed you will get a small window pop up telling you it is now ok to install the card in the computer.
Vista drivers http://kb.netgear.com/app/answers/detail/a_id/744
Turn off the computer, put the card back in, restart the computer. It will likely find and ask for the drivers again upon restart, just point it to the location of the driver and let it do its thing if it wants.
Once done the card should work right again, if not let us know, or is that's how you're doing it to start with let us know that either way.