Hey got some new info on my problem :-

Restore Missing CD or DVD Drive
Reports have filtered in that CD or DVD drives will suddenly cease to exist in XP systems. Most often this has been reported in conjunction with program installations and Windows upgrades, but it has also happened for no apparent reason. This tweak will restore the missing drives after a reboot.


[Start] [Run] [Regedit]
Registry Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class
Key Name: {4D36E965-E325-11CE-BFC1-08002BE10318}
Value Data: [Delete All Value Data from UpperFilters and LowerFilters]
Note: Do not delete the Key or the Multi-String Values. Delete only the data values.
Exit Registry and Reboot


i think that will solve my problem however i dont know what it means when it says "Delete All Value Data from UpperFilters and LowerFilters" ?
Any help plz.