Why Dose Flash Slow My Computer

I have a brand new computer that I built last month. It has a Gigabyte-4 quad bios motherboard, AMD Phenom x4 quad core CPU at 4.2 GHz per core, and 16GB of ram, and two 500GB hard drives, and SLI with 2 GeForce dual core GPUs. I'm Using Windows XP SP3 2008 Edition. Every time I get on a site that has flash of any kind it almost stops my computer dead in its tracks, and maxes out the CPU 90 to 100%.
I contacted AMD and they say its NOT the CPU, that it is a software issue

I need to find out what is causing this and how to fix it, since almost every website today use flash of some kind. I do have the latest version of flash installed as well with all of the software on my computer.

Please help, Thanks