On my system I have just replaced HD 3450 crossfire with on board graphic with the new Zotac gts 450 .
i have unstall ati drivers but ati catalyst center still shows when i right click opening box on monitor.
how to remove ati cc from box. it doesn't goes.
second thing do i have to reinstall the games to get better frames rate from this graphic card. or i have to format C drives and reinstall all the things again.
"i right click opening box on monitor. " You mean when you right-click on the desktop, you can still see a link to ATi CCC? Go to Control Panel->Add/Remove programs and make sure it has been uninstalled properly.
And no, you won't have to re-install any games or programs for them to work with the new card. Just make sure you remove the ATi drivers and install the Nvidia drivers.