For u BF2 player high-end spec's

Video.con

This setting controls your current resolution in Battlefield 2. The format is Width x Height@Refresh Rate. If you cannot start up BF2 and change the resolution from within the game, try altering it here to help you startup the game. In particular when you want to launch BF2 for the first time and the game just crashes back to desktop (See Troubleshooting Tips section), you can change the resolution from its default of 800x600@60Hz to one your monitor supports. Note however that certain resolutions are unsupported and entering them here will not work - see the Command Line section further below.

VideoSettings.setTerrainQuality 4
VideoSettings.setGeometryQuality 4
VideoSettings.setLightingQuality 4
VideoSettings.setDynamicLightingQuality 4
VideoSettings.setDynamicShadowsQuality 4
VideoSettings.setEffectsQuality 4
VideoSettings.setTextureQuality 4
VideoSettings.setTextureFilteringQuality 4

All of the above settings can be adjusted from within the in-game Video settings. However the highest they can be set to is High from within the game (a value of 3). By setting them each to 4 in Video.con (as shown above), you will have them displayed as 'Videosettings_Ultrahigh' in the in-game Video settings screen, and some people believe this increases the graphics quality to Ultrahigh levels. I didn't see any impact from this change, but if you want the absolute best quality in BF2 give it a try.

U'll find the video.con file in the \Documents and Settings\[username]\My Documents\Battlefield 2\Profiles\ directory

Source: http://www.tweakguides.com/BF2_1.html