Running Adelphia Powerlink on my Surfboard 3100, so I have some experience with this.
First, shutdown Windows, then unplug the cable modem to reboot, don't use the power switch on it if there is one, you want it to do a cold reboot, which requires all loss of power. Plug it back in, wait to get all 4 lights back solid then you SHOULD be ready to go. Boot up and run as usual.
Second, does it take a long time to boot up?? This could indidcate a problem with your ISP, and maybe their servers are losing track of your MAC address. You MUST call your ISP for that one !! Don't wait !
Lastly, this works for my 3100, in your web browser, even when your not online, type in teh address of 192.168.100.1
This is an HTML page hardwired into the cable modem for diagnostics, and might be of SOME help to your ISP.
DO NOT HIT THE BUTTON IN THE HTML PAGE WHICH SAYS TO RESET THE CABLE MODEM !!!!!!! I have no idea what this does and you've been warned !!!!!!!!