at last i found the solution .while i always encountered this problem after i reformat.
Try doing the following:
1) Make sure the resolution you want to run is supported by your graphics drivers.
If you can select a resolution in your Operating System, then it is supported.
2) Backup your registry, in case something goes wrong.
START > Run > regedit > file > export
3) Change Warcraft 3's resolution manually.
START > run > regedit
While in the Windows Registry Editor (regedit), locate:
HKEY_CURRENT_USER > Software > Blizzard Entertainment > Warcraft III > Video
4) Make below change in decimal format:
(Right click > Change > select "decimal" > fill in new value)
reswidth = 1600
resheight = 900
Replace width & height with whatever resolution you wanna play in, examples:
852x480 16:9 Widescreen
1280x720 16:9 Widescreen
1365x768 16:9 Widescreen
1440x900 16:10 Widescreen
1680x1050 16:10 Widescreen
1920x1200 16:10 Widescreen
320x240 4:3 Aspect ratio
2048x1535 4:3 Aspect ratio
Subject: TUTORIAL MAKE A WIDESCREEN GAMING OF LAPTOP 
Tue Nov 30, 2010 11:10 am
