Compaq SR2010NX

Last year a few of us chipped in and bought a Compaq SR2010NX Desktop PC
for our neighbor. It was a special deal at Staples with a large rebate
(which we had no problems collecting.)

This year I'd like to get her a DVD-RW since the system came with a combo
DVD/CD-RW drive. It plays DVDs but does not burn them. I'm debating
between an external DVD-RW or an internal (which is cheaper and my funds
are somewhat limited this year, I'm afraid). My question has to do with
the power supply in the system. From what I can tell, it's a 250w Bestec
ATX-250-12V. I'm concerned that it will not have enough power to add an
internal DVD-RW. I could replace the combo drive, but I"m not sure I want
to do that either.

Any thoughts as to what's the best route for me to go? Would an internal
DVD-RW work with the current power supply or would I just be better off
going with an external? Many thanks.

Patty