In January, 2007, I purchased a new Dell Dimension E521 desktop computer via telephone. The machine was sent with Windows XP 2000 installed and, as agreed, I was sent Microsoft's Vista upgrade later. Upon installing the Vista program, all sound disappeared from my computer. After 10 months of wrangling, I have reinstalled Windows XP. Even though both products were new and should have been workable, both companies showed minimal interest in helping. However, both agreed to assist if I agreed to pay hefty hourly fees. Obviously, I have purchased my last Dell product and will certainly avoid Microsoft products in the future whenever possible.