Can't get a certain resolution to work?

[xpedient]

My video card is an ATI Radeon HD 4650 Series 2gb
My LCD monitor size is 18.5

In my desktop, I am using a resolution of 1366 x 768.
In games, I also use a resolution of 1366 x 768.
The problem is that some of the games like Dead Space 2 or Heroes of Newerth (which I am currently playing) has low frame rate when I am using high settings. So I want to check if I tried a lower resolution with high settings to get some of that lost frame rate.

The problem is that whenever I change the resolution lower than 1366 x 768 and "higher" than 1024 x 768, the game crashes. This doesn't happen on Dead Space 2 only, old games like Warcraft 3 (DotA) can't use resolutions higher than 1024 x 768 (was trying to get to 1280x768 or 1280x1024).

Even in windows (desktop) I tried to change the resolution to lower than the said resolutions but there is an error message and it said, "Windows could not change your display resolution. Try a different resolution."

Please do move this thread if I posted in the wrong section... Thanks in advance!

 

[jasonalwaysready]

for best results, keep your game running the native resolution of your monitor. if changing the graphics level lower doesnt help out enough, it's time for an upgrade.

 

[suppahigh]

you really don't want to play games on resolution lower than 1024x768 even on 18'' screen instead try lowering the game settings to medium lets say or leave them on high but disable any AA that should improve your frame rate. updating drivers also helps. i'm not sure how often ATi release drivers and i've heard that its not that often at all but never the less you should try and get the latest drivers.