Hi QueenEBee:
Ok, so defiantly not a virus or malware and probably not a signal strength problem if you can stream from other sites without a problem.
Which web browser are you using? What's your system like i.e. CPU, Ram, video card, operating system?
I have a pretty high end system and generally I don't see excessive cpu usage by IE or FireFox when watching videos from the Xfinity web site, usually the Flash plugin in FireFox uses 4-7%. I suggest rather than Windows task manager that you try using Process Explorer http://technet.microsoft.com/en-us/sysinternals/bb896653.aspx, if you are using FireFox then process explorer will be able to show you the FireFox plugin container and the detailed Flash processes and you should be able to see if Flash is what's hogging your CPU. One thing you can try is to check your Flash settings and see if you have hardware acceleration on or off and try and switch the setting, sometimes it will help and sometimes not but it's worth a try.
- Norm
