Windows 7 Troubleshooting Wireless Mouse Not Working on Windows 7 Despite Keyboard Functionality

System Restore back to a time before you installed the mouse and keyboard combo. You may need to clean your registry as well, to clean house. I would think that the major problem in this instance is that because its multiple HUDs (human interface devices) on one port, moving them about via different USB ports could confuse the OS, and the registry, in the process. In fact, you don't know whether or not when you moved it if you moved it to a separate USB controller on the board. I would suggest going back to a time before you installed it, if you can, and start all over again. Get it into the port you want, and leave it there, mindful of the fact that this mouse/keyboard combo may not be the best setup given the circumstances. So I would:

Restore back to a time before the problem and if that's not possible get backup mouse and keyboard.

Run a registry cleaner to clean house after uninstalling both the mouse and keyboard drivers.

Re-install the drivers first, and per-instructions install the devices to the port you're likely to keep it on.

Be mindful of not moving it to a different USB port or controller given the fact it sees to have interoperability issues based on how the devices are being recognized, and possibly written to the registry, by Windows.

When you connect any human interface device to your computer, a registry entry is created for that device. You are in a unique situation, in that you are using a combo mouse/keyboard device on one USB port. This could create a unique set of circumstances where, if you removed the device very quickly and plugged it into a separate port, you would have problems getting both devices to register. The safest bet are the above options. Just remove everything and start over again by using a backup keyboard and mouse.