Assuming you're using Windows XP:
The configuration software that ships with wireless cards often conflicts with XP's built-in wireless configuration utility, causing problems such as the one you describe. What basically happens is that either the Windows software or the card's software will take control of the card's functions, preventing the other utility's settings from having any effect.

To see if Windows is handling the wireless card:

* Right click on My Network Places and select Properties.

* Right click on the Wireless Network Connection icon. In the resulting context menu, you will see an "Enable" or "Disable" option; click that option and see what effect that has. If you seem to able turn the wifi card on/off by that method, do the following to see if you can release control of the card to the card's utility software:

* Right-click on the Wifi connection icon again, choose Properties, and then click the View Available Wireless Networks tab in the resulting Properties window.

* Check the status of the Let Windows Confiure my Wireless Network Settings option. If the box is checked, uncheck the box, click OK to apply the change, and then reboot the computer. (Note that your wifi card's software may have a similar option. If so, make sure that the setting of that option is set appropriately as well.)

* Once rebooted, see if the card's software can now control the card.

Thanks for your help.

Much appreciated!

You're welcome
Let us know the results of your troubleshooting....