I have bought a new macbook in july it was working fine upto today but I am getting the problem with my macbook. Later than inquiry the Mac create tone normally if you seize down C it will boot from the Mac Install/Recovery disc or if you compress cmd+option+P+R it resolve rearrange the PRAM or cmd+option+V should illustrate the unix method boot up series. Nothing of these shortcuts appear to be effective on my Mac and it boots directly keen on Mac OS 10.5, any thoughts why there not functioning and how I can get these startup shortcuts functioning once more? I want suggestion to get the desired solution please suggest me . Thank you.