Windows 7: Flash video disconnects modem and internet

Whenever I try to view video on youtube or any flash my windows 7 machine
disconnects the Huawei modem (even with updated drivers and firmware) and
thus also the internet access.
Non-video internet works fine. The very same modem don't disconnect during
video-viewing when installed on another machine!
What to do? Have tried everything.

Welcome aboard, Samahita

You should look for if there is any malware playing this role behind flash player. Sometimes ffdshow can cause such an issue if corrupted (I have the experience of using Huawei, with more or less similar issue). Download , install and upgrade the Malwarebytes Anti-Malware PRO free version, and have a full scan using it.

At the same time, update flash player (Adobe - Install Adobe Flash Player, uncheck the McAfee option before clicking the download button).

And , better you may opt for updating your video (including directshow) codecs : Get Shark007's FREE Codec solutions - Windows 7 codecs

Let us know how it works after those.

Malwarebytes found 1 registry key, which removal did not affect the issue.
Neither did installing flash or shark7 codecs.
The issue seems to be most common when load is high.

In that case, it would be the same for the other machines, but it is not, as per your first post

A Huawei modem is able to get upto 7.2 mbps bandwidth , so if you think that the service is the issue, you may opt for a better one. There are nice providers around.

But, load may lead to buffering, not disconnecting .