I have been on Tech Support Guy and I have looked at this site for a solution and have not found anything that works so I hope someone can help.
Here are tips that have already been tried...
Disable virus protection...
Download Adobe FlashPlayer from... http://www.softwarepatch.com/internet/flash.html
Although the source of this problem is with Youtube, most users have corrected this by following these simple steps:
1- Delete cookies, clear history, reset web settings and all internet options to default.
2- Remove Google toolbar or any pop-up bloker
3- Remove all version of adobe (reader, flash,etc)
4- Download this file and save it on your pc: http://www.softwarepatch.com/internet/flash.html
5- Restart your pc
6- Disable your Antivirus
7- Run the file you saved earlier
8- Enable your antivirus
9- Re-install Google toolbar
10- Enjoy watching Youtube.