I have a Dell Optiplex 780 running windows 7 and I have been having very slow upload speeds lately, and because I believed it to be my Modem/Router I purchased a new one but, I am having the same upload issue as with the old modem! I'm not sure what info to post here! I have Comcast Xfinity which they checked and confirmed as working normally. Download speed is better then excellent, I have replaced Ethernet cable, reset modem 3 times! I have tried everything I can think of that might effect uploading this but so far, no luck. Any help would be appreciated.