Roland GR-540 User Manual page 368

Search the list for Printers or Other devices, and then double-click it. The
name of your machine or Unknown device appears below the selected
item. Click the name to select it.
From the Action menu, click Uninstall.
On the Confirm Device Uninstall window, select the Delete the driver
software for this device check box, and then click OK. Close Device
Manager.
The name of your machine or Unknown device appears below the selected item. Click the name to
select it.
Disconnect the USB cable from the computer, and then restart Windows.
Follow the procedure in "Uninstalling the Driver (Windows 7)" and
uninstall the driver.
Follow the procedure in "Installing the Driver for Windows" and reinstall
the driver from the beginning.
http://startup.rolanddg.com/