I got a new SAMSUNG SyncMaster 2033sw, monitor, as my 10 yr old Philips has been running into issues for quite some time now. My PC in Neyveli (hometown) runs on AMD Athlon 64 on a ASUS A8V-VM series motherboard.
The display adapter is an on board solution provided by VIA/S3G.
When I connected the new monitor, the screen resolution was 1024 x 768 and the maximum supported by VIA/S3G Deltachrome IGP is 1280 x 768. This new one has a optimal resolution of 1440 x 900 (32 bpp). Searching on internet on various forums made me feel bad on choosing a wide screen monitor. Everyone said that a BIOS flash was required, which I least preferred.
But a simple driver update left to Windows Hardware Update utility did the trick. All is needed is just a Update Driver using the Add/Remove Hardware Wizard.
So Just update the driver if you are running into issues on the resolution. If that too doesn’t help, then resort to flashing the BIOS.
Edit: Download driver for Windows XP.