Why would a monitor remain in power save mode after installing a Radeon 9250 graphics card?
I would suggest updating drivers before installing a new video card however if you already have the card in and have yet to install the drivers, a possible work around is to boot into windows safe mode hold f8 after turning on power this should bring up a boot menu choose safe mode, from there you should be able to either update drivers (not sure if this is possible in safe mode) or choose a generic video display adapter then restart and update drivers.