That's my question regarding Windows 8.1 and also 8! I'd no problem with that Mouse on Windows 7 but Windows 8 and 8.1 Driver an required Apps installed ok. Problem start's if need to repair the mouse with the Laptops WiFi! At the first start of apps is installed, the pairing process works well. If, for any reason the connection to the Mouse is gone, need to be repaired again using the installed apps. It will pair for about a second and than lose the connection again. Only way is to un-install the apps and driver which are closely bundled together, restart the Laptop (required) and re-install the apps, than can pair again one time. That gets boring and as usual, HP support didn't answers any e-mail. The HP Service of HP Thailand in Bangkok didn't have any single techy who knows about anything of that Mouse! I like that Mouse because works better than any Bluetooth Mouse I tested and keeps the needed USB ports free for using. So, my question is: Is there any user with some experiences with that Mouse? Thanks for any answer that could help. Edit: This is strictly regarding an WiFi Mouse and NOT an Wireless Mouse. This one uses the WiFi of the laptop and NOT any Receiver! Thanks.