What OS is installed in your desktop?
Any other USB devices connected to the desktop? If so, how many and what are those USB devices?
Start by confirming that the correct mouse driver is indeed installed on your desktop.
If the correct driver is installed again download the driver to the desktop via the manufacturer's website, reinstall, and reconfigure. The existing driver may have been corrupted during the installation process.
Where is the desktop located - under a desk, off to the side...? Try a known working USB extension cable to raise the wireless receiver up and away from the desktop, nearer the wireless mouse.