Hi guys, I bought an iMac in mid 2010 and it was excellent, but it's getting so slow and sluggish now I've gotta do something about it. I keep my apps pretty clean, I've used CleanMyMac to clear the junk out, upgraded to 16GB RAM, and it still feels sluggish. Even compared to my little 13" 2010 MBP. The hard drive is constantly making the "thinking" sound as well, which gets pretty annoying, although I don't know if it always did that, or I'm just looking for things to notice now. Since I've tried everything else, I guess I'll go down the old Windows-esque route and format/reinstall. I seem to have lost the recovery disc from my iMac, but I've still got the one that came with the MBP - is it fine to use this? I ask because the disc does specifically say it's an MBP disc on it. Both Snow Leopard btw. I am intending on upgrading to Lion, but I want to upgrade from a clean Snow Leopard install, putting Lion on top of the mess I've currently got sounds like a headache waiting to happen. Before I go through the headache of a backup/format/reinstall, does anybody have any other suggestions as to what makes OSX get slower over time? People always say "You don't need to ever reinstall OSX, it's not Windows..." - please prove that right! Thanks in advance for your suggestions.