Before you dive into that, can you confirm that you're seeing the same problem that I was?
Are you getting the same weird failure messages, and more crucially, do you have IDE drives showing as SCSI drives in device manager?
If yes, did your DELL come with a system drivers disc? If not, is your laptop a Dell Studio 1557?
I did a quick search for you which only produced more questions:
Did your laptop come with Windows 7 installed, or was it upgraded from Vista?
I ask because I see that in July last year, Dell released a firmware upgrade for your optical drive which, I quote, "adds support for windows 7"
If your laptop came with windows 7 preinstalled, you shouldn't need this update.
If not, and you performed the windows seven instal yourself, then you could well be needing
this firmware update from Dell.
Please exhaust all other advise and options in the thread I linked to before resorting to running the update. It's not a driver, it's a firmware update for your hardware that will change the operating parameters of your optical drive, and should only be used once you've determined that you really need it.
-marko.