Hi, recently I bought a new keyboard with multimedia keys Model : Microsoft Wireless keyboard 1000 All the keys are working fine, I also installed the latest drivers and Intellitype Pro to the correct OS i'm using. However, when I press the mute/unmute button, the volume bar shows up, but does not actually mute. It seems like it flashed the mute symbol for half a second but it still just stay unmute. I tried using the default Microsoft sound driver and the latest Realtek sound driver but still no luck. I also tried turning HID services on and off but still the same BUT, I remember the mute button WORKING until a few days ago. I don't know if it is due to the Windows Update, or something to do with my motherboard driver or something else. The roll back driver option is greyed out in Device Manager so I don't assume that is the problem.. I'm currently using: Windows 7 Ultimate 64 bit Microsoft Wireless Keyboard 1000 YAMAHA speakers YST-M15 (really old model) Realtek High Definition Audio Driver 184.108.40.20659 ASUS M3A78-EM Motherboard I'm really confused because if all the multimedia keys are working then it should not be a driver problem. If the volume up/down is working then it should not be speaker problem. It is ONLY the mute button that is not working. Thanks in advance for any replies.