Thanks to all the help from this forum, I've got two older iMacs up and running as if they are nearly new again. There are better ways to do this for better performance and speed. People will probably add those methods, enclosures, and connections below, but as someone new-ish to messing with iMacs and the OS, I only wanted a super easy and cheap fix so I could see something work before I invested any more time and money into it. I had a smaller iMac and the larger 27" one, both 2011ish, and you could actually hear the Hard Drive start up with an un-co-operative attitude, and besides the loooong startup time, just coming out of sleep mode was ridiculously slow. Between that and actually browsing online or opening files, I stopped using both of them about a year ago. The poor, lazy, uninspired man's fix: I got a $15 Sabrent USB 3.0 to SSD /2.5 Inch Sata External Shockproof Aluminum Hard Drive Enclosure (looks like those orange LaCie external HD's but all black- and there are cheaper ones, but this way I could use it for something else down the road) that holds a regular SSD and connects by a regular SATA connection included with the enclosure, and the other end is a regular USB wire. And I put a cheap 128GB $40 SSD from Amazon into it and just used the USB connection (not the fastest I'm told, but works excellent for me) and booted from it with directions on Google/YouTube. It's like night and day, I have both machines as my main daily work units, and I run them like they're stolen- no sleeping or pausing all day, they are on and running 12+ hours every day 7 days a week. The only time I notice any slowdown is if I open too many tabs (way more than 20) while researching something online. No expensive enclosures, opening up the iMacs, pretty much no effort and less than $60 in parts per machine, and those are items that I can use for other stuff once I move on to another iMac. I only use them for web browsing and watching videos (online and iTunes) and it was the best shortcut I've benefited from since switching to Macs. Thanks to all those who answer silly questions by noobs on this forum, and apologies to those who told me better ways that required a little effort.