Hello,
Recently switched from Windows XP to Windows Vista Home Premium. Now I lose my Comcast ISP connection approximately after going online about 10 times. Comcast says press reset button in back of cable modem, but it is stuck and will not move. They also suggest turning off modem and or rebooting computer. Sometimes this works. Sometimes I have to contact Comcast and have then reboot my service. This always works. I get this message: "The computer could not get an internet connection. Call your ISP for further assistance.  Error AC-3001; err 0x84100118, OS Vista; ACS 4.6.61.1; TCP/IP Connection No IP Routes; Firewalls: Norton Internet Security
Any help would be appreciated.
Thank you

First thing, have you informed Comcast about the stuck reset button? This would seem to be capable of creating problems.
I am also running Vista Home Premium and had the same problem with connections to AT&T [formerly SBC].
After research on the problem, I finally found out that my dsl modem was only a modem, whereas later signups with the service got a combination modem\router.
At that point, I went and got a router. This seems to have solved my problem.
I don't even have to go through the connect to Internet routine in Vista, the router automatically connects when I turn on the computer.
Don't know if this would help you or not since you have a cable modem.
If you haven't informed Comcast about the stuck button, I would do that first. The modem itself may have intermittent problems due to the button.