Hi Bryan,Ahh, the power of lateral thinking! It took a couple of attempts to get this set up - I didn't realise that the available keys to use were limited to those in the drop-down list in the FS2 Config Manager.I eventually selected TAB as my mute button, but when I attempted to select this as a key command in FSUIPC, it refused to acknowledge that I had pressed a key! Using my newly-reminded lateral thinking skills, I instead held down the TAB key and pressed ` (the key in the top-left corner, to the left of 1) which FSUIPC recognised. Checking this in-sim, and it works like a charm, provided you remove the tick from 'Key Press Not To Be Held' in the 'Buttons + Switches' tab of FSUIPC.Just thought this would help other laterally- challenged users!Thanks for your download support and this little issue, Bryan!CheersRobP.S. Couldn't find reference to the other program in the manual, but I think you may be referring to JoyToKey, which I think would also do the job if you don't have registered FSUIPC.