yikes lol there's some rough advice here. You definitely don't need to wipe your drive or start fretting about hackers lawl...
One possibility is that your browser is set to allow content from youtube but 'forgot' to allow content from propoolvideo, if you have some kind of flash blocking plugin. A lot of programs that are made to block popups and ads will accidentally block flash videos that you want to watch. A common one for firefox, NoScript, requires you to click an icon to allow a site to play flash videos. You might have something similar you can click to allow propoolvideo.com.
If that isn't the problem, it couldn't hurt to clear your browser cache/temporary internet files.
If that doesn't fix it, the only application you should need to install (or reinstall) is flash player 9. The videos are in flv (flash video) format... which is playable with just flash installed and nothing else. I don't believe you need quicktime or any other codecs.
The latest version of flash (version 9) is at:
http://www.adobe.com/products/flashplayer/
It should quietly detect your browser and OS and the next page will be a download link for the version that's right for you. It's possible (a bit unlikely) that you have a version that's new enough for youtube to be happy with it, but not new enough for propoolvideo.com.
Recommend that you uninstall the old version manually (through the start menu if it's listed there, or under add/remove programs if it's not) before reinstalling with the new version.
If all of this sounds like gibberish it's because I'm assuming you're on windows, but if you're on a mac... maybe someone else can chime in :X