Maybe something on your broadband setup disk clashed with your wireless driver, i had the same prob when connecting my mates pc to his bt home hub (using the bt installation disk), i ended up doing a system restore then setting up the wireless manually.
You could try that: Start > Programs > Accessories >System tools > System Restore, then Restore to an earlier time > Next, then click a bold date (before it all went tits up) on the calendar, see if that restores your wireless driver/icon.
Alternatlively you maybe able to restore the whole pc back to its factory state using either the restore disk which came with it or with a built in restoration utility, not sure which applies to time pcs.
If you dont fancy that then get it back to the shop and flutter yer eyelashes/kick off.