Please go to the Apple logo at the upper left of your computer screen to About This Mac and give me this information: Version (under Mac OS X) Processor Memory
processor: 2.4 GHz Intel Core 2 Duo Memory : 2 GB 1067 MHz DDR3
Open Macintosh HD / Applications / Utilities and double click Disk Utility. Highlight your hard drive, usually Macintosh HD, and click on Verify Disk on the far right. If that is OK in green type, then click on Repair Permissions on the left.Note: If Verify Disk is not OK try to Repair. If Repair is successful then Repair Permissions if it is not successful let me know.