1. Right click anywhere on the desktop and choose display settings option.
2. At the top of the page, your available monitors will appear as numbered boxes. Select the monitor for which you want to change refresh rate.
3. Under related settings section, choose Advanced display option.
4. Click on the refresh rate dropdown available at the bottom left corner and choose the desired refresh rate from the dropdown (25Hz recommended for new monitors in office with Lenovo docking stations)