Flashing W850i

Okay, my w850i has the weird white flashing screen, i read the tutorial on how to flash it using SEtoolLite 1.1 and when it asks me to Press C and plug the usb cable in, my computer shows a message saying that the USB device is not recognised... what do i do?

Also, how do i know which files to download to properly flash my phone.

Clean phone connector!

It works for any other phone except this one ... :|

did you clean the fastport connector like senter advice?

replace the plug in the charger connector ...