Recently I have been having problems with my iMac like mail and safari crashing when you click on something for example printing and causing you to have to restart the computer by holding the button in. The interesting thing is this is only happening when logged in to 1 of our 2 profiles. I have also noticed that I get the waiting beach ball thing more often on both logins. I am pretty sure that a restore will fix these problems but I want to know if there is anything else that I can try. Also if I have to end up restoring how long will it take? I have about 450gb of data on the computer and i am backing it up using a seagate hard drive which is only connected to the mac through a usb 2.0 port and a 2011 21 inch base model iMac.