http://support.microsoft.com/default.aspx/kb/314060
< add a bit >
First thing is to check to see if it is being picked up in the BIOS. If it is not there check your Cables. Try another Cable. If BIOS cant detect it then replace it. If it is there try the steps below.
Common BIOS entry Keys
F1
F2
DEL
ESC
F10
A user will know when to press this key when they see a message similar to the below example as the computer is booting. Some older computers may also display a flashing block to indicate when to press the F1 or F2 keys.
Press to enter BIOS setup
Tip: Hold a Key down, this will cause a stuck key error, which may allow you to enter the BIOS setup.
If the CD/DVD is not showing in Device Manager follow these directions for clearing the Upper/Lower Filters
Click on Start, Run and type in 'regedt32' and press Enter
Expand the "HKEY_LOCAL_MACHINE" key by clicking the "+" next to it.
Expand the "SYSTEM" Key
Expand the "CurrentControlSet" Key
Expand the "Control" Key
Expand the "Class" Key
Look for a key containing the following string of letter and numbers:{4D36E965-E325-11CE-BFC1-08002BE10318}
High light this key by left clicking on it
On the right hand side you are looking for "UpperFilters" and "LowerFilters" under the "Name" column, once you find these Keys delete them by right clicking on them and choosing "delete" exit the registry.
Restart your PC.