not getting update driver

hello i have instal aurduino uno in my window 7 32 bit when i update driver manually but aurdino uno inf file not found now wat i do????

Is it a real Arduino Uno, or does it use a different serial chip? The cheap ebay clones usually use CH340G serial chip, which you need to download separate drivers for (google will find the drivers no problem, it's a super-engrishy installer, but the drivers work fine) - to see what serial chip you have, look at the chip closest to the USB port - it's either a CH340G (common on clones), an atmega 16u2 (used on official, and the closest of clones), or FT232R. The FT232R drivers are included, but there are still some clones that use non-functional counterfeit chips making the rounds, though most of them are out of circulation by now (google ftdigate for details on that mess).