How to Reset MacBook Memory

Shut down the MacBook by clicking the Apple Menu and clicking 'Shut Down.'
Start the MacBook and immediately hold down the 'Option,' 'Command,' 'R' and 'P' keys.
Release the keys when the MacBook restarts on its own.
VPS Hosting

How to Restore Imac to Factory Settings (16 Steps)

Insert the Mac OS X Install DVD into the iMac optical drive with the computer running. Restart the iMac and hold the 'C' key while the computer restarts. This forces the computer to start up from the DVD.
Select the language when prompted and press the 'right arrow' key to continue. Click 'Utilities' in the menu bar and select 'Disk Utility.'
Click 'Macintosh HD' in the Disk Utility window and select the 'Erase' tab. Click 'Erase' to erase the hard drive. This process completely deletes all applications and files stored on the computer. Be sure your data is backed up before erasing the hard drive.
Click 'Erase' when promoted to confirm the selection. After the process is complete, click 'Disk Utility' in the menu bar and select 'Quit Disk Utility' from the drop-down menu.
VPS Hosting