LG DVD RAM GSA-H42N doesn't play cd or dvd and won't burn

Hello there.I was here on Saturday and posted a question and got no reply and that’s why i’m reposting my question 2day.I got the above writer not up to 3 months ago,but really just started using it like a week ago.Last Friday i used it to burn a cd but on Saturday it won’t burn or play cds which it used to do.I tried to boot an XP CD with it but it won’t boot but goes on loading the previous XP installation.The DVD RAM icon shows in My Computer but when i put any cd it won’t change to cd icon to show there’s a cd inside and won’t play using Real Player or Windows Media Player as it says there’s no cd in drive.Please what can i do as this is a new drive?