You've not said what happens when you try to view a YouTube video. If you see the YouTube webpage as normal, except that there's a blank space where the video should be, it means that there's a problem with the Flash player on your laptop. (Either it's not installed or it's not functioning properly).
Go to 'Add/Remove' programs and uninstall any references to Adobe Flash Player. (If Flash is installed, but not functioning, you'll probably find 2 programs to uninstall. If Flash isn't on your laptop in the first place, there will be no references to Adobe Flash Player and you won't have to uninstall anything).
Then download and install the free Flash player from Adobe:
http://www.adobe.com/go/BPCKK
Chris