I have an early 2009 20" 2.66 GHz Core 2 Duo iMac which has recently been upgraded to a 1 TB Green Caviar Western Digital Drive and 8 GB RAM. I did a clean install of Mountain Lion on the new hard drive and restored the users via Time Machine. The hard drive is less than 2/3 full. What I am running into is the spinning beach ball when I click on my login before I even get to type my password. It is always of a different length so I can't find a correlation. I also get it randomly when using different programs. The only one I have noticed from Activity Monitor is that Flash usually tops out my CPU performance. That would be fine if it was the only time it happened but it isn't. I have very little third party software on here but I am looking if anyone has any brilliant suggestions to help overcome this. Someone had suggested I remove the password for my user, then add it back due to some issues with the keychain, but I couldn't find specifics on how to accomplish this to see if it would actually work.