Check the resolution in the eqclient.ini file, you can find instructions in this thread:
http://www.project1999.org/forums/sh...ad.php?t=94928
but they should be set to something like:
WindowedWidth=800
WindowedHeight=600
Width=800
Height=600
FullscreenBitsPerPixel=32
FullscreenRefreshRate=0
WidthWindowed=800
HeightWindowed=600
If that doesn't fix the issue others have had success with updating their video drivers, but the above seems to be the solution to most of these.