I went to a little bit of hell when upgraded my Dell Alienware m17x to windows 7 64 bit ultimate. It's been working great for a while but out of no ware the HDMI output stopped working. I check the HDMI cable but it was a good cable. I could not get my HDMI working to my external dell 24" monitor nor my HDTV. After digging around I went to dell.com downloaded the latest BIOS driver for A03 release on 1/11/2011. To to dell.com and get the latest windows 7 BIOS driver. http://support.dell.com/support/downloads/download.aspx?c=us&l=en&s=gen&releaseid=R254103&SystemID=ALW_LP_M17X&servicetag=&os=W764&osl=en&deviceid=19197&devlib=0&typecnt=0&vercnt=4&catid=-1&impid=-1&formatcnt=0&libid=1&typeid=-1&dateid=-1&formatid=-1&fileid=372828
After updating the flash bios it started working like a charm.