From what I can see of your mobo at the Jetway site, it's a 200MHz CPU used. No option for 266MHz. Therefore nope. The largest CPU you can have is an Athlon 1.4Ghz 200MHz FSB. Not a bad CPU, a bit slower than an XP1500 or 1600, but pretty good though.
<b><font color=blue>~ Oh flower of Scotland...da da de de dum dum doo doo.~ </font color=blue></b>