Dell powered by Windows 7 Home Premium Freezes.

Hi guys I need some help from some of you computer guys. Lately my laptop has been freezing up while trying to play videos online via YouTube, Live Leak, etc. It will not play sound at all and video skips stops for a few seconds then picks back up where it should be. Example I start video at 0:00 seconds, it will play for 1 second the freeze the screen for 3 seconds then the video will pick up a :04 seconds where it would be as if it had never frozen. I remain in control of the mouse pad and cursor and can switch tabs, screens, click on other things but the video still is silent and freezing. I can play music stored onto my computer via iTunes just fine. Any ideas on how to fix this? I'll be running my scans again tonight. I ran them last Sunday and it came up clean using CCleaner, Clean Up!, Emsisoft Anti-Malware, and Malwarebytes Anti-Malware all programs installed by my Dad who told me to use them. I haven't de-fragged my hard drive in a while, could this be the problem? This is my computer:http://ps3-www1.us.dell.com/us/en/g...-n4110/pd.aspx?refid=inspiron-14r-n4110&s=gen
Thanks for any help, honestly it may have been a blessing in disguise this week being that it is finals week, but I'm done with them tomorrow after history(no problem) and math which shouldn't be to bad.

 

Thanks for the help guys! lol jk I'm sure someone would've come to help me eventually but with a call to an IT friend that works at my school we got it fixed just had to reboot and update. Whoops