If it works on other pcs it doesn’t sound like a problem with the flash drive. I would suspect your machine’s security apps are preventing access ot the drive. Or maybe you use other USB devices in the same port? Windows is notorious for assigning the same drive letter to different devices.
I don’t know what to tell you about the driver problem. If you have the Windows 7 System Restore function enabled restore the system to a point prior to your changing the driver.
