I am a new iMac user. I bought the computer about 6 months ago. My sister has been a Mac user forever but even her is clueless about my problem. Many of my applications (explorer, quicken, excel, word) quit afer they are opened and I try to type. I can't open system preferences, I can't drag anything from the desktop and I can't reach the apple menu becuase the bar disappears everytime I click it. What is going on? My daughter's account is not suffering from this. Any ideas about how to fix it. PLEASE HELP!