Hello and Welcome to our forum devil_mix!
From what you said....I believe you either have only power cable installed....or your drive has some serious problem!? Btw...you can open a drive, put a CD in etc..etc...also when only power cable is on....but it wont be visible neither in BIOS neither in WindowsXP that way....so please check again if both cables(power and data) are correctly attached?
Then let me know....to find other solution (but first i need to be sure that both cables are correctly installed!).
Good luck 4 now...
EDIT : And in case you share that IDE channel with some other device(like Hdd or another optical drive)...check that they arent both set as MASTER! Set HDD as Master and NEC as Slave in this case...or put it on second IDE channel....and if its the only drive there...leave it as MASTER!)....