how do I find the iWork 09/Pages serial number?
History: 2 years ago I bought a vintage iMac that came with iWork 09. It has been functioning fine. The hardware limits my updating, so I can't do Yosemite, but that's not a big deal for me. Last week the iMac started running slow so I installed a virus protection (Sophos), cleared my Cache & Browser History and downloaded a supposedly free MacKeeper - but MacKeeper wasn't free without purchasing stuff, so it "corrected" 500+ things and said it had 1200+ left to do if I bought the program. I did not buy.
Problem: Now when I try to work in Pages, I get this error message: You can't save, print or export documents until the iWork 09 30-day trial has been activated. Click Learn More to purchase iWork'09 or activate the 30-day trial. Then a screen pops up with buy or try and asks for a serial number.
What I've tried: I downloaded the most recent update possible successfully (no error message) so I'm thinking it restored my iWork program - NOPE, same error message appears.
My guesses: MacKeeper screwed it all up. It did not download fully, so I cannot uninstall it since it just did a minor/partial "cleaning" and I think it corrupted my iWork software. If that's the case, the iWork 09 update wouldn't have downloaded successfully (there had to be intact software to update or it wouldn't have updated).
What do I do now? Is there some way to find the serial number since my iWork software was installed by the seller and there is no disc? Or is there something else I can do?
iMac, Mac OS X (10.7.5), iWork & Pages Problem