I will claim no level of intelligence above garden tools from now on...I really messed up. I read an article about how you can speed up Safari by deleting quicktime extensions in Safari, and instead found Quick Look in my activity monitor on my 13 inch Macbook Pro, and deleted it. Now, there are no previews for any photos, and it just shows blank icons with jpg written, no actual picture. I cannot import photos from my iphone 4s anymore into itunes or even my SLR digital camera into iPhoto or Adobe Light Room, keeps saying jpgs are unrecognizable format. Anytime i save a photo off the internet I get the spinning beach ball of death, my macbook pro slows down and i have to always wait a minute for the spinning ball to go away as my macbook saves the picture. -forgot to mention on initial posting I deleted the Quick Look system files from finder too- I tried to download Quicklook plug in, mainframe, from developer sites, no dice...I can't seem to get back what I deleted in my less than smart move Can anyone please let me know what I can do to fix my macbook? OS X Yosemite 10.10.2 (14C109) MacBook Pro (13-inch, Mid 2009) 2.26 GHz Intel Core 2 Duo 8 GB 1067 MHz DDR3 NVIDIA GeForce 9400M 256 MB Thanks!