Lenovo B550 User Manual page 77

If your product is not working correctly,
DO NOT RETURN IT TO THE STORE.
For technical assistance, contact a Lenovo support specialist 24 hours a
day by calling toll free 1-877-4 LENOVO (1-877-453-6686).
Additionally, you can find support information and updates on the
Lenovo Web site located at http://consumersupport.lenovo.com.
* Only for the users from the United States.