If you are pressing and holding the pairing button on your mouse for over 10 seconds with no response from your computer, here are some possible solutions to get your Bluetooth Mouse working.
Check the blinking light is working when you press and hold the pairing button. the light is not blinking, it may be a faulty mouse or the batteries may be dead.
Next check the batteries on your wireless mouse. If the batteries are running low, your Microsoft surface won’t detect the mouse.
Check to see that your Bluetooth is turned on. Hit your start button. From there you go to Settings > Devices > Bluetooth & Other Devices. Check to make sure your Bluetooth is on.
Try using the wireless mouse with another computer. If you are able to get it working with other machines, but yours still is not working, it may be an issue with the software on your computer.
Start your Bluetooth troubleshooter. Press the start button and go to settings. From there you go to Update & Security > Troubleshoot > Bluetooth > Additional Troubleshooters. This will pull up a list of options. Select Bluetooth and Run Troubleshooter. Follow the on screen instructions.
Update Bluetooth Drivers. Press “Windows R” to bring up the Run Box. This will appear as a small window with one input box. Enter “Devmgmt.Msc” and press okay. This will open the Device Manager. Scroll down to Mice and other pointing devices. Click on the link and it will open a short drop down menu. Right click on the HID-compliant mouse and select Update driver. This will update your Bluetooth driver. Follow any on screen instructions and then restart your computer. Test to see if this resolved the issue with your Bluetooth mouse.
Update Windows OS. If you are working with an older version of Windows OS, it may interfere with your ability to connect to Bluetooth devices. In order to update windows, hit your start button, go to settings. Scroll down to Windows Update, and Check for Updates. If there is an update available, you can install it and then restart your device after the installation is finished.
The USB Dongle is damaged. If you are able to plug the mouse in directly with no issues after all troubleshooting techniques are exhausted, the dongle may be damaged.