Problem in reading and writing dvd and cds

[qanda]This question is published in the hardware section for the Matshita UJ-850S. Click here to view full specs.[/qanda]Hi,i have a sony vaio VGN-CR11GH laptop,wid matshita UJ 850s dvd/cd rom,since 18 months.After one year it was unable to read cds,now it is unable to read both cds and dvds also. I am using vista as os,i also tried a lot by changing the burning application,and also reinstalled the os twice,but no use The vaio hardware diagnostic report says that the drive is working correctly,but the drive is not working. pls give me a help in this aspect