Install the Windows 7 version of the wireless driver. Even better: install the Windows 7 versions of all drivers your laptop needs and doesn't have yet. Device Manager will help to identify them, I suppose.
I have clean-installed Windows 7 on a laptop, but my wireless Internet connection doesn't function anymore. I have a livebox (I'm in France) and I have another laptop that detects perfectly the livebox and has a good Internet connection. This second laptop has a wifi card that seems to be functionning (I checked in the Device Manager), yet Windows doesn't seem to be able to detect any wireless networks.
I'm sure there's something idiotically easy to do to fix this, but I have no idea what. If you need more info, please ask me.
Thanks in advance!