Dell computers have proprietary Hardware, and I have always used their Dell Recovery Discs to reload the OS on the new HDD. A colleague of mine did the same thing on a Dell computer, Cloned a HDD and installed it. A few months later it failed, so I would guess there is something Dell doesn't like in the Clones. So I would say, get the proper Dell Recovery Discs and reinstall the OS that way. You can get the Discs on the Dell Web Site for a nominal fee.