I have been using two USB display adapters (USB video cards) to connect windows 7 laptop to multiple monitors.
All worked well, then after I tried to connect it to different monitor, windows 7 no longer recognizes the USB display adapters as video adapters.
When I plug them in, I am told the drivers installed, its ready to use, but nothing after that.
In device manager, they appear briefly under Other devices, then disappear
any ideas ??