Computer help forum: Wireless USB adapters 2 at a time?

I purchased a wireless USB kit by Ultra and then also got USB to Wireless HDMI kit from Diamond. Both of them were to be used on my work bench which is not too far from my computer. My computer already has three monitors and this wireless HDMI kit connects to the fourth monitor.

The kits use the same software to manage the wireless USB radio host. It's called plain & generic "wireless USB manager".

The only caveat is that they work fine when I use only one at a time. When I plug in both, the wireless HDMI kit works fine but the wireless USB kit doesn't do anything. When I first installed them, I installed the program that came with wireless USB first, then Diamond's Wireless HDMI - the latter uninstalled the former and took over both kits. It was showing two adapters in menu but only the video was working.

After rebooting and plugging and unplugging both kits, now it only sees one (video) If I disconnect and reconnect Wireless USB it says "Channel 13 is busy". I can switch to different channels but I get the same results. Even when I disconnect the wireless video adapter, I get nothing.

Is this a design flaw? since Windows shows no error message and both adapters appear to be working but the USB port on the adapter is unresponsive? If there is no work around, I can live without wireless USB and it wasn't very expensive. It is most likely a software issue. Any USB geniuses here?