Since nothing works, you have nothing to lose by trying this:

In the Device Manager, Uninstall EVERYTHING Under "Universal Serial Bus 
Controllers."  Then reboot and let the machine reinstall what it detects. 
You might want to check for drivers from Toshiba prior to doing this for the 
USB Controller, but I believe somewhere in this thread you had & there were 
none.

This has worked for me before when some persnickity Pocket PC drivers have 
trashed all my USB functionality.