How do i get rid of this comcast self activation page that keeps popping up?

when i paid the bill late now we have this self applied activationb page that jumps up randomly when i try to reach certain website pages comcast is actually no help in any way! anyone in addition have the following happen along with any suggestions

Go for you to Start
Programs
Accessories

where it states that “command prompt”, RIGHT click it, and decide “run as administrator” on the drop decrease menu.

An “elevated command prompt box” will appear.
Enter:

ipconfig /flushdns

inside black command prompt package and click enter.