Definitely Vista compatible.. HMM.. It's hard to tell with Vista; it could be anything. Might I suggest disabling UAC and trying it. I doubt that's what it is, but UAC is annoying anyway. Start - Run - msconfig - Tools - Disable UAC - Launch. Start - Control Panel - Classic View - Security Center - Change the way Security Center alerts me - No alerts, don't show icon in system tray. Reboot, re-install, try again. I wish you luck, sir.