Olee has a hard drive that is full and he's going to put in a new hard drive with Windows already installed. Leo says that won't work. Windows won't just turn on due to Microsoft Genuine Advantage. Olee would have to format the hard drive and start over. He'd need Windows on a disc to reinstall it, though. Leo hates that computers are sold without OS discs anymore. It's a very shortsighted point of view, and manufacturers do it because of piracy concerns.
Leo recommends Olee call Microsoft and explain his situation and perhaps they'll activate it. But Olee will have issues with drivers being incorrect and more from the other hard drive. It's easier to just go online and buy the discs outright. They're on eBay all the time. The other option is to call the manufacturer (in this case, Dell), and ask for system recovery discs. Dell will probably send them for a nominal fee.