Currently Being ModeratedNov 21, 2012 2:52 PM (in response to James Merolla)
Legally the Mountain Lion installation is actually tied to the person who purchased it and put it on the MacBook. He/she should have removed it before sale as well as provided you with the original disks.
Your best bet now, if you cannot get the original disk from your seller, is to contact Apple using www.apple.com/support/contact if you are in a country that supports it or call the appropriate phone number on this page, they can send your the original disks that came with the computer for a minimal fee.
Best of luck.
Currently Being ModeratedNov 21, 2012 6:16 PM (in response to laundry bleach)
Wow, so what do you think the seller did so that when I opened up my computer it was a new setup screen for Mountain Lion?