Flash drive installs as unknown device

i have an attache' 4g flash drive that worked fine. it's loaded with hunderds of dollars of software that i need to write the programs that i make for people. i've tried everything mentioned so far and still to no avail.

i'm getting a message upon installation of the device that says the device is unknown.
i've even tried reinstalling the driver software. in the "computer" window there is no icon to click on to ope of explore the device. please help