Epson Perfection 640U Reference Manual page 97

If EPSON Perfection640 appears under Other devices with a
question (?) mark
Note:
Make sure your scanner is plugged in and connected to your PC. If your
scanner is unplugged or not connected to your PC, you cannot reinstall
the driver properly.
1. Click ? EPSON Perfection640, then click Remove and OK.
2. Click Close to close the System Properties window.
3. Shut down your PC and unplug your scanner. Then turn on
your PC and plug back your scanner.
4. The following dialog box appears. To install the driver again,
follow the instructions in your Startup Guide.
Maintenance and Troubleshooting
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