Acer 4420 Notebook does not see Linksys rou...

I have an Acer Extensa 4420 Notebook and after downloading a Windows Search update, it no longer sees my Linksys WRT54G router. Prior to the download, it worked fine. My router does show occasionally in the Wireless Connection box but my notebook does not connect. I can run a cable from the router to my notebook and that works fine.

To date, here is what I've tried:
1. Uninstalled the wireless network adapter and reinstalled.
2. Checked for updated drivers.
3. Re-uploaded the firmware for the router.
4. Powered off the computer, router and dsl modem. Powered up the dsl modem, router and then the computer.

The only thing I haven't tried(yet) is doing a hard reset of the router.

Any help is greatly appreciated.

Mike.