Apple MacBook Pro Laptop Computer with Intel Duo Core 15.4 Inch PC Notebook "sense key error" Questions

...Sense Key = MEDIUM ERROR' and 'Sense code = 0x73, 0x03'. Is this a dirty lens? It can be dirty lens/ drying laser or glitch in software.. Clean your lens, check for laser adn reinstall drivers for ...

...Sense Key = HARDWARE ERROR, Sense Code = 0x03, and from Apple Hardware Test: 4SNS/1/40000000:TCOP. Are they related? What's to be done? Restart your computer, when computer chimes during restart, ...