If you can not use your computer with the frequency setting, please follow the steps below:
1. Restart your computer and enter safe mode.
2. Select "Use VGA mode" in safe mode.
3. Click [Start] - [Control Panel] - [Display] - [Change Display Settings] - [Advanced Settings] - [Monitor] - Select screen refresh rate to 60Hz and apply.
If the problem still persists, please set the resolution to the minimum and then change the monitor's resolution.