YouTube & Internet Explorer: this video is no longer available

When you use Microsoft Internet Explorer 7 or earlier to watch YouTube videos, it often happens that you are told:

This video is no longer available

even though you know that the video works with Firefox, Opera, or other browsers.

In that case, it is a proxy issue. You are trying to download the video with a proxy that is incompatible with YouTube. A very typical example is Google Web Accelerator, a program that should speed up the internet traffic by using a Google proxy. If you use it, the fix is simple: right-click the accelerator icon in the tray and stop the accelerator.

If you still haven't fixed it,

1. try to download hotspot shield that gives you a new proxy IP address to download from the U.S. YouTube (most complicated)
   
2. or try to change/increase the quality by attaching a "fmt" parameter to the URL, e.g. http://www.youtube.com/watch?v=WQyMnoYqguo&fmt=6 - here, the numbers 6,18,16 at the end can give you nontrivial results. A new server may be chosen.
3. choose your own proxy. In Menu / Tools / Internet options / Connections / LAN settings, check the "use proxy" switch and enter 213.42.1.19 as "proxy" and 8080 as "port". Answer the dialog boxes and try to view the videos.