OK, so I haven't tried moving the computer, yet, but I did get another wireless dongle that I like better, anyway, and it came with an adapter to allow me to place it somewhere away from all the other possible interference. This did not resolve the issue. Then I tried disabling the firewall and watched several videos that had previously caused the issue, and the issue did not reoccur. So, I'm thinking it might be the firewall. I will just try disabling the firewall before watching any streaming videos and see if that's all it was. If it turns out to be something else, I'll come back and report that.
In the meantime, does anyone know why, if it IS the firewall, it would stop the video at the 10-14 second mark, and then not allow ANY other internet connection, even just switching to a new tab in the browser? I'm curious as to why that should happen. The software is AVG Internet Security 2013. The computer is Dell Optiplex GX620 Dual core 3.0 GHz Pentium running Win XP pro. My speccy is on another thread regarding sound issues.
I honestly cannot think of a reason why a firewall program would do that unless it is some strange settings. Generally, firewalls with either let something happen or it won't let it happen at all. So, I would think the firewall would either not let the video play at all or let it play.
About the only thing that I can think is that there is some setting that might be confusing that the "excessive" data download for the video with some sort of nefarious thing. But, that would be more the anti-virus/malware side of things then kind of "telling" the firewall to shut of the Internet connection. And frankly, I am not really aware of any consumer level security programs doing that kind of thing. As I said, it is usually a "block" or "don't block" scenario right from the start.
I suppose it could be that there is a bug in the firewall or something similar that gets "triggered" when you have a lot of data being downloaded. In other words, you are "overloading" the system in some manner such that it kill the Internet connection. And somehow it only gets triggered when the firewall is active.
I suppose you could try a different security program.
I did find this thread that suggests it might be an issue with AVG:http://productforums.google.com/forum/#!topic/youtube/IBV1trPM8l8
They were specifically talking about YouTube videos, but it might be the same thing. You could try what many in that thread did...turn off the AVG Accelerator that appears to be part of the AVG security suite.