Lucasfilm, along with PC manufacturer Dell, has announced a new program that grants THX certification to PCs. The first PCs to carry the THX license are Dell's 8100 and 4100 series, meaning that both types of computers come equipped with THX-certified Dolby Digital Surround speakers and software, which let you adjust your computer settings to the optimal visual standards set by THX. The software also guides you through speaker placement and sound card adjustments to ensure the best possible sound quality. THX-certified PCs are thoroughly examined to measure the level of audio and visual performance as well as to ensure that there are no other factors that might hinder performance. The THX-certified Dell computers come with the THX Optimizer software and a DVD containing trailers to show off their video and audio capabilities.