Yes, your product key is the 20 digit number in the system properties.. this is *not* the install product ID, the product ID was either on an orange sticker on the back of the jewel case ( for retail ) or on a certificate of authenticity sticker on the computer, or on the front of the windows 2k manual ( oem ) ...do not assume that you will be able to install 2k from the 20 digit key, you will need a five segment 25 digit key that is alphanumeric ( RPV46-FJKCX-342fx, blah blah blah, if you don't have that key, and you have an original CD and jewel case, MS will take the coding on the inside ring of the original CD and the cd set on the back of the jewel case as proof of purchase and provide you with another key in most cases