My brother has just jumped on the Mac bandwagon and has bought himself a new 21.5-inch 4670 iMac after years of persuading him to ditch PC . He's only had it a few days, but he fears he may have messed things up with the audio after downloading and installing 3rd party drivers to make his existing external audio interface compatible with the iMac. This is the problem as he describes it: I first downloaded the UA25USBDRIVER from Edirol (Roland) and then installed it. However my audio interface (Cakewalk SPS-25) did not work therefore I uninstalled the driver with the uninstall option which came with the download. I then downloaded the SoundBlaster.USB.Audio.Support.pkg from the following site (had to register first): http://www.insanelymac.com/forum/index.php?showtopic=34075&pid=705315&mode=threaded&start= then further down the page is the link for the driver: http://forum.insanelymac.com/index.php?act...ost&id=5069 Only 1 file downloaded (the .pkg file). I installed it then restarted with the SPS-25 connected. SPS-25 did not work. No sound from iMac. iTunes won't play music. Nothing recognised in System Pref/Sound or Utilities/Audio. Magic Mouse will not scroll. Keyboard volume buttons don't work properly (volume up brings up dashboard, volume down minimises windows (sends them to different parts of screen) and mute takes my active window to the centre of the screen and darkens everything else around it). Same situation after restarting with the SPS-25 removed. Needless to say I was hoping my brother's first Mac experience would be a positive one . Short of a OS erase and re-install, is there any way to fix this?