TigerDirect TigerDirect inc. When computer does not work, I am told that I must take the problem up with Joy System because they own the HP system Atlanta, Georgia

I spent all that I had on a new computer but the Internet Explore and Display Drivers turn on and off, the computer runs loudly. I call them tigerdirect.com many time but tigerdirect.com send me to Joy System. They tell me to return the computer but I can be without one, and they may not follow through. I have a HP DC7800 Refurbished Destop PC - Intel Core 2 Duc 2.33ghz, 2GB, DDRe, 500GB HDD, DVDRW, Windows 7 Home Permium 32-bit (Off Lease).  I have comcast high speed Internet and I don't understand why it continue not to work. I had several people including Joy System tell me that the motherboard is AMD and the computer has a Vista display driver, something that I really tried to avoid, based on their bad reputation. Unfortunately, this computer isn't what it should be and I am very un-happy. Why can we be fair in America!