I have a usb wireless plug on my PC too.
When I start my comp, it showed limited connections
I dunno why, maybe some guru will advise.
Below steps works for me.. 
+++++++++++++++++++++++++++++++++++++++++++++++++++++++
If wireless icon at botton right screen
Step 1. Point your mouse on the wireless network icon,
Step 2. click on right mouse button
Step 3. click repair
Otherwise Click Start menu, control panel , network
connection,
wireless network goto step 1, 2, 3