GPIB-USB-HS won't communicate

I have GPIB-USB-HS connected to a dell desktop with Windows 7. I have tried using two separate desktops (same make/model) and cannot communicate with any instruments connected (HP33120A signal generator or HP34401A multimeter). These computers have not previously had any GPIB cards.

I have tried pluggingin the adapter into the usb port of the computer and connected it to either instrument and allowed windows to find the driver and uninstalling said driver (and all of my NI software) and installed the most recent driver from the NI website. I have done each of these with the adapter not plugged in, plugged in with no instrument connected, and plugged in with an instrument connected.

The adapter's yellow light next to "ready" is on. When I had no drivers for the adapter, the green led next to "active" was lit. With no drivers, viewing it in MAX would show me a details page that read "Windows does not have a driver for this device." When I have the drivers installed and I scan for instruments, I get a message "Instruments not found." A screenshot of the MAX page and my device manager is attached.

What else can I try?