ATEN KN Series 32-Port KVM over IP Switch with Dual Power/LAN (1-Local + 4-Remote Access) - Manual (Page 291)

Appendix
273
Additional Video Resolution Procedures
If you are running Windows, and wish to use new refresh rates, do the
following:
1. Open Control Panel
→
Display
→
Settings
→
Advanced
→
Monitor.
2. In the dialog box that comes up, make sure that the Hide modes that this
monitor cannot display checkbox is unchecked.
3. Click the arrow at the right of the Screen refresh rate listbox, and select
the refresh rate you want from the list that appears.
Note: Make sure that your monitor supports the refresh rate you choose – if
not, you may seriously damage your monitor.