okay well you found the guy to answer the q.

im a computer repair tech and actually own my own busness (which some of you dont know)

[email protected]

and how you can tell is to go into your device manager.... (and im assuming you have windows XP home edition)
you will see a screen like the one im posting... it will list the hardware by name (ie. cd-rom,cd-rw,dvd/cd-rw16x etc.)

just click the (+) under cd/dvd drives and it will tell you
(but the pic is from a winxpsp2 platform, yours may be different)

i can help with anything else... just let me know