If you've got a USB cable (such as the one you may have just moved for a firmware update), all you have to do is pick an input (I used Aux for some tinkering last year), set it's audio input to "USB" in the setup menu (USB is an alternative to analog, optical 1 thru 5, and coaxial 1 or 2), connect the laptop to the 990 with the USB cable, and making some sound on the laptop (Windows Media Player, WinAmp, iTunes, game, whatever). The 990 will be recognized by the laptop when you connect the two and treat it similarly to a USB sound card. A mini-jack to RCA connector would work, but would be of lesser quality (I doubt the laptop sound card's DAC is on par with the 990's DAC).