Computer freezes when playing videos online

I've had this problem for a while but it's getting really annoying now. Almost every time I try to watch a video on Youtube or any other website, my computer suddenly freezes for a couple minutes. It's impossible to watch even a 5mins video without any problems. I figured that this has something to do with the flash player / plug-in....I use Chrome. Any idea how to resolve it?

Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows 7 Home Premium, Service Pack 1, 64 bit
Processor: Pentium(R) Dual-Core CPU T4400 @ 2.20GHz, Intel64 Family 6 Model 23 Stepping 10
Processor Count: 2
RAM: 4024 Mb
Graphics Card: Mobile Intel(R) 4 Series Express Chipset Family, 1820 Mb
Hard Drives: C: Total - 226373 MB, Free - 119408 MB;
Motherboard: Gateway, SJV50MV
Antivirus: Norton Internet Security, Updated and Enabled