I'm new to arduino, and any help would be really appreciated.
The very first time I connected arduino to my W7 laptop, it worked like a charm, installed new device drivers successfully, uploaded my sketch (which still continues to run every time its powered). I checked device manager and it showed the arduino under COM/LPT ports.
Then, after disconnecting the arduino and reconnecting, it no longer shows a COM/LPT section and instead shows an unknown device under USB. Every time I've tried uninstalling driver and reconnecting, it keeps giving me a driver installation failed error.
Googling for the issue told me to "update drivers" manually using the .inf provided with the Arduino installation through device manager, but when I tried that, it says the drivers aren't compatible with Windows x64.
Another tip from an arduino forum user told me to copy the arduino.inf into C:/Windows/inf, but that didn't solve the problem either