Wireless problems on an Acer desktop pc running Vista

Had problems with my computer over the last few weeks, and I think I have finally got the thing up and running again. Had to remove some RAM, restore back to factory settings etc. All because it kept freezing on me after a while, but my net connection (via wireless) was fine.
Obviously after I restored it to factory settings I lost my wi-fi (Netgear) sofware, and so last night I installed it again and put the adaptor into the USB port and so that is done and installed. It shows a connection and the computer can see my household wi-fi netowrk with a good signal.
But I can't connect to the internet, or even tweak my settings. Never had this last time when I first set up my wireless connection when I got the PC.

When I look on the desktop toolbar there is the icon of the two computer screens with the red cross through it. If I hover over the icon it says "Connection status: unknown. Access is denied"
So I went to try and have a look at or tweak the settings under the Network & sharing centre in my control panel and when I opened that up it didn't give me any options it just read "Unknown. Access is denied"
Can anyone help me?
Thanks

Were you using the internal hardwired connection before you installed you wi-fi?
If you were try this, disable your hardwired connection, make sure the wi-fi connection is enabled and reboot and see if you can connect.
I had this same issue with a system I just rebuilt. I had to disable the hardwire connection, rebooted and I got connected. Go figure. Have you tried the wireless manager to see if you can get connected?

Thanks very much for your reply. Those are suggestions I haven't heard before which is great and something new for me to try.

I have always just used wi-fi on this PC via a Netgear USB adaptor. I have never taken an internet connection through a wire.
Would you be kind enough to explain how to do the procedures that you posted above? I'm not very good with computers and so I'm a bit lost. I would be really grateful if you could talk me through it a bit more.

Thanks again.

Click the globe in lower left, right click network, in the popup window select "properties", in the window that open click "manage network connections", right click the adapter you want to disable and select disable.