How to increase screen resolution in W7

Hello
My Window7 family ed is installed on an old machine and my problem is the following:
- my screen hp le1901w have a definition 1440x900 and operate on another distribution ( linux in dual boot ) as per this resolution
- for W7 the max in the menu is 1280x 1024 and no other larger resol appear in others menu
I try to modify in regedit / video / X resol & Y resol and replaced 1280 per 1440 and 1024 by 900
Anyway no change in screen resol menu ; still 1280 x1024 ; this make a large difference
Note : for this resolution in linux I had to add some functions in startup sequence , this means this resolution is not recognized by the old BIOS ( I suppose, try to update my BIOS but not possible it seems , original from 2005 ) ; in W7 drivers for screen is for hp screeb while for graphic card it's a windows standard.
here screen data( from linux) :
Graphics:

    Device-1: AMD RV280 [Radeon 9200 SE] driver: radeon v: kernel

    Display: server: X.Org v: 1.20.4 driver:

X: loaded: radeon

     unloaded: fbdev,modesetting,vesa

dri: r200 gpu: radeon - resolution: 1440x900~60Hz

osenon said:

- my screen hp le1901w have a definition 1440x900 and operate on another distribution ( linux in dual boot ) as per this resolution
- for W7 the max in the menu is 1280x 1024 and no other larger resol appear in others menu

Have you downloaded and installed the Windows 7 drivers for your screen from HP?

HP LE1901w 19-inch Widescreen LCD Monitor Software and Driver Downloads | HP(R) Customer Support

yes the driver is dedicated to screen ho le 1901w ( and appear in driver's menu for monitors )
But for the graphic card , no , I can't find a dedicated driver for it , only the window's standard

have you read this,

Adjusting the monitor settings, Using the on-screen display menu | HP Monitor LE1901wm User Manual | Page 21 / 45

I confirm the HP monitor is correctly configured : the max resolution is 1440x900x60 and dully operated as with the other system ( linux antiX , which is a " old type" distro )
the matter is the W7 configuration settled at max 1280x1024 ( probably du to regedit config and /or graphic card driver )
I suppose W7 can operate a monitor at it max resolution......

You are going to need a OEM driver to get better resolution for the graphics card. The problem is the newest driver is only for Windows XP. 12 years ago somebody else found out that driver didn't work very well with Windows 7.

ATI Radeon 9200 driver for win7 problem!!
ATI Radeon 9200 driver for win7 problem!!