How to change screen Resolution?

Linux and Unix-Like Linux
1

Dear all
I install Cent OS 5.5 ( Linux OS), with bshell and also Windows OS on the my laptop (ASUA) maximum screen resolution in Windows OS is 1024*760 but in Cent OS 5.5 is 800 *600, I have a program that is necessary to install on Cent OS and I have problem with other Linux distributions for installing this program,
Please guide me how can increase screen resolution, or other solution if there is
Best regards,
Mary

2

What is the output of the following command?

# xrandr
3

i have typed " xrandr", it answers

 SZ:    Pixels          Physical       Refresh
  *0    800 x 600    ( 271mm x 203mm )  *61  
   1    640 x 480    ( 271mm x 203mm )   61  
  Current rotation - normal
  Current reflection - none
  Rotations possible - normal
  Reflections possible - none

Please guide me how to increase screen resolution.