Dell Optical Drive Not Reading Discs

hi,my dell stuhdio 15 doesn't read any custom discs(i.e which i burned using my system) after i installed windows7 but it reads the disc drivers and OS DVD whic are given by dell! i checked the custom dvds in my system and also in my bro's hp laptop it reads them perfectly...here is the problem posted in technet(which found by googling) but no solution offered!!
Drive Model-TS-T633A
plz help me solve this peculiar problem

 

What kind of disks (Music, data, etc.)?
Describe what you're doing and any error messages.

 

It reads all types of cds perfectly but in dvd it reads only dvds which i got while purchasing my laptop all others it just makes some noise after i insert and it automatically ejects itself after some time and after which it shows "plz insert...".I dont get any error messages!

 

Be more specific. Does it read movies? Is there any region coding involved? Do you have the proper codecs installed?