Wireless networks not appearring (except one)

Here's my problem. I upgraded a Dell Optiplex machine that was running Vista to Win 7 (both 32 bit). That went swimmingly. However, when I now check my wireless networks, only one available network appears.

there are 8-10 networks that show on two other machines in the same room as this machine. One is a laptop that I place right next to the Vista to 7 machine that is causing me the problem.

It is possible that during the upgrade the Vista machine was connected via the one network that still shows. I don't know that for certain, or if it is even pertinent. However, that network is not properly secured. One of the other (i.e., missing) networks is the one this machine needs to connect to for security reasons. (We're in an office suite and the network that shows up is a master; one about which we have no say regarding its security.) That's why I have to make the other networks reappear.

I've looked at a bunch of other posts but don't see anything that seems to help with this issue. I don't know where to even start (other than I have rebooted; twice). I am suspicious of the Windows firewall but all other programs seem to work - except printing (I guess because that printer is wirelessly connected on that missing network).

Anyone got an idea of where I should start or what I need to do to get this back to normal? I am in need of some serious help ... and this time, that doesn't mean a mental professional

Thanks

Thank you so much. The device manager said there were no drivers installed. I hit the update button and it fixed it immediately.

I wonder how it saw the one wireless network it saw.