Lenovo 43R1802 Guia Del Usuario página 40

Before contacting a Lenovo technical support representative, please
have the following information as possible: option name and number,
proof of purchase, computer manufacturer, model, serial number and
manual, the exact wording of any error message, description of the
problem, and the hardware and software configuration information for
your system.
Your technical support representative might want to walk you through
the problem while you are at your computer during the call.
For a list of Service and Support phone numbers, visit
http://www.lenovo.com/support/phone.
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