how can i install drivers for vga controller.... plz help me solve my issue.. thanks

Welcome to D-A-L.

Well it would help us to help you if you provided some details about your machine.

Download, install, and run Everest Home Edition (CLEAN FreeWare) on this machine. Once it's finished loading and running, look under;

MOTHERBOARD
Post what is listed for your Motherboard (make/model) and the Motherboard Chipset description.

*** AND ***

Computer, Summary, Display, or under Display, PCI/AGP Video. This will tell you what display adapter/chip you have. (Video Adapter and 3D Accelerator.)

Post that information exactly as presented by the program.