I cannot see any videos in YouTube?

If you are running Chrome or Firefox, make sure you disable any plugins you may have.

Thanks Tom:

I provide some additional details about my problem:

I have tried with various laptops in other networks and youtube can be seen OK (even in networks much slower tan mine) but they fail in my network.

I have installed the new Adobe Flash Player and tried Firefox and Explorer and the result is the same: any video stops at 0:00 and it stands just there for hours (the best result is to see 2 seconds of the video).

YouTube is not blocked in my country.

I have to admit that I am stumped. The only things I could think to check would be your router – is it somehow configured to block youtube traffic? What about your hosts file? Both of these things could be tinkered with by a friend as a joke.
Another thing that comes to mind is your ISP. Years ago, I realized that my ISP was content-filtering, which was resulting in me being unable to use bittorrent.
Sorry, these are probably insufficient to diagnose your problem. Good luck – and keep us updated if you find the solution.

I read your question and posts in details and don’t think that you should face a problem then but in case you are having trouble why not talk to your connection provider about it. Make him aware of that. In case he takes time in fixing that, make sure to try watching youtube videos that are uploaded on different site. This could help you fix the problem. See if you tube videos are working on other sites then there might be several other reasons why you can’t access youtube videos directly from their site. Get them fixed with your vendor ASAP.

Thanks Tom and Magdalene. I had a “normal” router and a router for the WiFi. I phoned my ISP and got my “normal” router changed. This new router was also a WiFi router so I switched off the old WiFi router and the problem disappeared. Now I watch youTube videos fantastically fast. Great!! Thanks again for your help.