As long as it is the same make and model TiVo you can swap the hard drives. You will probably have to do a Clear and Delete everything once you put in the new hard drive before you can use it.
For future reference - there are companies (such as dvrupgrade) which sell drives with the TiVo software on it as well as a CD with the software you can copy to a blank drive you purchase. Usually cheaper than buying a new unit and you can put a much larger hard drive in your TiVo for more recording space.
For future reference - there are companies (such as dvrupgrade) which sell drives with the TiVo software on it as well as a CD with the software you can copy to a blank drive you purchase. Usually cheaper than buying a new unit and you can put a much larger hard drive in your TiVo for more recording space.