cd rom

as i asked about the cd rom windows dont reconize or supports the cd rom.
i have an acer aspire 5515 notebook, came from factory with vista home basic, cd rom is a optiarc ad-7580s scsi. when i first purchased it i got to use cd rom four times playing dvd's with factory install of windvd, then it stopped. i had problem with acers softwares causing problems that i bought a system builders disc of win7 home premium and the cd rom still wont play dvd's. in registry edit theres no value set. theres no upper or lower case filters. i've done everything suggested and still cant get it to work.
my question is Are cd roms interchangable? can i interchange the optiarc ad 7580s with a lite-on DS-8A3S.
in bios the optiarc is listed.

You can buy any CD/DVD-ROM that you want and replace the one that you have, as long as it uses the same connections to the motherboard (IDE or SATA). To make sure, just bring the broken one with you to the store, and someone can help you find the correct replacement.

but i wouldnt want to spend the money on one and still have the same problem.
acer has done something here that prevents you from booting from the internal cd rom. to boot it up, i had to buy a external cd rom. for some reason acer emachine and gateways are like that. support techs arent knowlegeable to help with issues. to resolve issues with corrupt files is factory default restore, thats putting it back to the way you purchased it. which thats thier only help with any issues. thats if you can understand them. they do not speak english clearly.

Normally you must configure your BIOS for the proper boot order. So you need to go into the BIOS and set it so the first boot device is the DVDRom. The problem is likely because you mention the device is SCSI (this is not very common any more). You might have to pick a boot option like "SCSI" or "OTHER" and set your SCSI controller to boot (and no I don't know how, it's just something I read in researching the issue).

thanks, i went in device manager unstalled the optiarc 7580s, shut down, installed the ds-8a3s cd rom. worked fine, started flickering at first, went in device manager and scan for hardware changes, retried work good.
i looked up on some laptop forums and found a link on one for acer laptops, it had this aspire 5515 listed with other 5515's listing all the hardware and the optiarc 7580s was not listed, the 7690s was. booting up from cd rom acer has that disabled, you have to boot from a external cd rom. acer isnt the best computer manufacture ou there i do not recommend anybody buying a acer emachine or gateway, cause all three are the same company. the aspire 5515 is also the emachine e620, but the 5515 doesnt have win7 drivers i used the e620 to resolve other problems.