There are times when we decide to go back to the beginning, and restoring your computer back to its factory state may be ine. If you have lost your restore dic, or have never created one in the first place, you can still contact your computer's manufacturer and request a replacement. Just be sure to have your unit's serial, and product numbers and/or its express service code.
Manufacturer - Contact Number
Apple 1-800-APL-CARE (275-2273)
Asus 1-888-678-3688 or 510-739-3777