Wireless mouse for laptop was working fine, but

Try disconnecting all external devices and reboot the unit. ( Includeind the wireless mouse. )
Next make sure your wireless network is also turned off.
Plug in your wireless recv. to a USB port. ( USB2 )
Flip the mouse over and look for a reset button on the bottom. If you have this reset button, reset it.

Allow you unit to find and reload the device drivers for your wireless mouse or load from manf. disks.
Check and see if the recv. is getting a signal.

Afterwards, you can plugin your other devices and turn on the wireless modem or network.

Hope this info has helped you.

Usually means the mouse is too far from the unit.
Try a diff USB port and get closer. Also make sure
the battery in the mouse is new.