Why can't i watch videos on youtube?

Try uninstalling it, then re-installing it, BUT instead of continuing, restart your system, if it doesn’t work after that, ask your parents to check it out.

we need to enable javascript. in firefox: tools - options… - content (Enable JavaScript). in IE and i recommend switching to the fox if IE is your browser: tools - internet options - security - (look at the bottom and click) Custom Level… - (scroll down and find) Scripting - (once found make sure) Active scripting is enabled. if not enable it and click ok. if IE askes if you wanna change just click yes.

even if it doesnt ask you to, restart your browser after the enable.

also if they still wont play then are you sure you have the correct flash installed on your system and the correct version of java?

may be u have not FLASH PLAYER installed.

Or your Antivirus can be blocking it. Norton did that to my friend - it can be a bit over zealous.

Or your firewall might be blocking it. Mine popped up one day asking if “plugin-container.exe” could connect to the internet. I was like WTF is that?? so I said no. Youtube stopped working :P. Turns out its FF new system for playing videos and such so if the video locks up it doesn’t crash your whole browser. I believe most other browsers have similar systems now.

Try disabling your anitvirus and firewall TEMPORARILY and see if that fix is it. If so one of them was causing the issue. Find out what is blocking to cause that.