Actually I've never needed a DVD drive before that's why a don't have one. I did have one in '98 but never found a use for it during the machines life (actually I did once find retail dvd's for 30 quid but it turned out my little 333 couldn't decode them without skipping a frame every couple of seconds).
And as my machine is a 2400+ with 1gig of ram, 120gb hdd and a 9800 pro yes I think it will run HL2 just fine thank you.
My main issue with this is I only want HL2 not Counter Strike, HL1 Source or any other bolocks they put on the dvd.
I tried counter strike quite a lot back in the summer of '99 - it was full of annoying kids then - why the hell should I pay for a dvd drive so I can not play it now???