Hi, Here are the specs for my mac: August 2012 13" MBP with Mountain Lion (OS X 10.8.2) Processor: 2.5 GHz Intel Core i5 Memory: 4 GB 1600 MHz DDR3 Graphics: Intel HD Graphics 4000 512 MB Hard Drive: 500 GB Memory: 4 GB Ever since I got this Mac 6 months ago, I've been occasionally getting a pinwheel of death which, once it occurs, can't be stopped/removed unless I manually turn off the machine using the power button. This pinwheel occurs most often when I am using Safari, Microsoft Word 2008, or Stickies. I almost always have both Chrome & Safari open at the same time (I utilize two different gmail accounts and use Chrome more for personal websites and Safari more for professional/academic sites), and I often use Word or Stickies and keep them open. When the pinwheel appears, I will try to force quit the offending program as well as the other programs, but then the pinwheel will appear while I am on the Force Quit window itself, locking all open applications. The same thing also occurred when I used Chrome and Firefox at the same time - originally, I thought Firefox was the problem but Safari actually seems to be worse sometimes. This kind of pinwheel usually occurred maybe once every 1-2 weeks, until recently when I began getting it every day. I took it to the Genius Bar where they ran a SMART Utility scan and discovered a few problems. Since I was under the warranty and I had backed up my computer before arriving, they decided the best course of action was to replace my hard drive. Unfortunately, I got the same problem right after bringing my computer back home from the repair, and now my Mac pinwheels and needs to be shut down manually at least once every day. I have tried a few things found from searching the Internet like turning off AutoFill in Safari, clearing my cache, opening only a few tabs at a time (usually maximum 6-7 on Chrome, only 2-3 on Safari), and repairing disk permissions. I ran a disk permissions check just now and this is what it returned: Verifying permissions for Macintosh HD User differs on Applications/.DS_Store; should be 0; user is 501. Permissions differ on Applications/.DS_Store; should be -rw-rw-r-- ; they are -rw-r--r-- . Group differs on Library/Java; should be 0; group is 80. Permissions differ on Library/Java; should be drwxr-xr-x ; they are drwxrwxr-x . Group differs on Library/Preferences/com.apple.alf.plist; should be 80; group is 0. Permissions differ on System/Library/Frameworks/CoreGraphics.framework/CoreGraphics; should be lrwxrwxrwx ; they are lrwxr-xr-x . Permissions differ on System/Library/Frameworks/CoreGraphics.framework/Resources; should be lrwxrwxrwx ; they are lrwxr-xr-x . Permissions differ on System/Library/Frameworks/CoreGraphics.framework/Versions/Current; should be lrwxrwxrwx ; they are lrwxr-xr-x . Permissions differ on usr/lib/ruby; should be lrwxr-xr-x ; they are drwxr-xr-x . Permissions differ on usr/share/zoneinfo/America/New_York; should be -rw-r--r-- ; they are -rwxr-xr-x . ACL missing on Volumes However, when I verified the disk itself, there were no issues reported. This problem is driving me up a wall and I would love to get some advice! The Genius Bar hasn't really helped me with these issues besides constantly ripping out and replacing my hard drives (I had issues with my previous Mac as well). In this case, I suspect that it is not my hard drive but my activity, but I'm not quite sure what because I never had this particular problem with my old MBP. Thanks for your help!