RE #2 & 3) You did NOT say so, but I gather that for both of them you're now talking about ON VISTA, right?
In any event, you do NOT need to open the case or unplug the card.
Vista has already TRIED to install the device, and if it is NOT working it will show up with either a yellow sign or red X over it in the Device Manager.
How to bring up the Device Manager (which may NOT be right for Vista...):
0) Start -> RIGHT-click My Computer and select Properties at the bottom of the pop-up.
1) Select the Hardware tab, then the Device Manager button.
You should now be able to see a list of devices in your computer, and one (or more) of them may have red or yellow marks on top of the device's icon.
2) Find the one for your "Network adapter" and DOUBLE-click it to bring up its Properties window.
3) Click the Details tab, then select the long line of text in the large pane on the bottommost part of that window and post it here. (It should look something like this: {1A3E09BE-1E45-494B-9174-D7385B45BBF5}\NVNET_DEV0373\4&26BB4C8F&0&00 )
4) "X" out of all created windows.
This will give me specific info about the device so I can look up the Visya drivers for you.