Hi Arlenedoll969,
PCs/Laptops usually don't come with an Activated copy of MS Office. Mostly all you get is a trial version. Accordingly, you would most likely have had to purchase a copy of Office in a box from a shop or online from MS. In the former case, the Product Key will be on the case the software came in. In the latter case, see:
http://support.microsoft.com/kb/823570