My computer was held in ransom and I looked for a reasonable price for a new tower on Amazon.  I found a rebuilt one and the price was great until I got it home.  It doesn't work!  It won't sync to my system.  All I get is a green light immediately turning to red and that's it.  I called in a computer tech and he agreed there is something wrong with the tower and to return it.  I'm seldom disappointed with products from Amazon until this purchase.