Have an HP TouchSmart 300. Had it registered with Product Key that came with computer. No problems. Had to send computer into HP for repair. The Product Key was changed by the person who worked on this machine. Neither Product Key will be accepted for validation by HP. Have many problems, one being can not install any downloads which HP sends to me to download. Another problem is I can access UAC but unable to change anything. I am listed as the Administrator and have no problem signing on and using the computer. After receiving the computer back from HP and using it for awhile I had a problem and had to reinstall the computer back to it's condition, not sure if something happened during that or not. Any help would be appreciated. Thanks Gary