make/model of router might be useful.. did it used to work? or is this a new setup? diagnosing net connection problems is usually a process of elimination. in no particular order: check the easy things first. change the phone/ethernet cables (use short cables if you can) - see what happens. have you put in a new phone? does it have a line filter on it? try unplugging all the phones + filters. have you installed any new software/hardware around the time the net started to cause problems? if so uninstall/remove and see what happens. take the router to a friends house (who has dsl) - try it. if good then the problems your pc or line. if still bad them the problems the router or your router settings. if the router has been reset to factory defaults as you say, then check the router settings have been correctly set to your ISP's settings (this should actually be the first step). Check PPPoE/PPPoA and VC/LLC settings match the ISP. Depending on how your ISP operates you can often still connect even if these are wrong, you just don't get a good connection. also check the MTU. try drop it to 1492 (factory default will probably be 1500). open the routers status screen and look at the "Line Attenuation" and "Noise Margin" numbers. (google them for an explanation). if you have lots of noise on the line this will cause connection problems. some ISP's have the option to drop your speed a little to improve stability. clear any proxy settings in the internet options unless your ISP tells you to use one.