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iMac (2007-2009) Memory Installation Video - YouTube
20-Inch iMac (2007-2008) Hard Drive Installation Video (iMac7,1 iMac8,1) - YouTube
Imac 7 1 Memory Upgrade
How to upgrade RAM in the (Mid 2017) 5K iMac and save up to ~$900 [Video] - 9to5Mac
iMac RAM upgrade: Here's an affordable way to improve multitasking - CNET