The monitor is displaying in what could be called portrait mode rather than landscape. That is, 768 x 1024 rather than 1024 x 768. This is not a rotation issue. The icons are all upright, the aspect ratio is reversed. The rightmost icons are off-screen. The graphics properties present only reversed ratio alternatives: that is 600 x 800 (not 800 x 600).
There are no (visibly running) worms or hacks or add-ins that affect video display. The machine long ago had a chinese character writing system on it but that has been uninstalled and removed as far as I can tell. There are no obvious "extra" running processes.
Drivers is version 10/25/2002 v 6.13.01.3317. Main driver appears to be ialmrnt5.dll.