my cpu is infected with spyware

I tried to view a video at a website two days ago which gave my computer a virus and Ive been getting pop ups ever since telling me that my personal information is being accessed. My internet explorer home page was hijacked immediately with spyware insisting that I download some antivirus protection right away. Today my internet explorer homepage just has the yahoo toolbar at the top of the page but the rest of the page is blank white.