After you make your EQ setup, there is a SAVE button to the right of the sliders.
Push that SAVE button, and then enter the name you want to save the EQ setup as. That setup will remain in effect until you change it.
You can save any number of EQ setups, and you will also be able to re-load them by name.
NOTE: You will lose all of your saved EQ setups whenever you upgrade Realtek audio drivers to a new version. That's because the so-called "upgrade" actually consists of two steps: (a) UNINSTALL current driver, and (b) INSTALL new driver.
And unfortunately that first UNINSTALL step deletes all of the Realtek Registry keys, which unfortunately deletes all the EQ setups since it is in the Registry that the SAVE process for an EQ setup gets stored. Too bad they don't put it in \ProgramData or \Users where it obviously belongs and could be preserved.
So be sure you write down how many +/- ticks you push each slider up or down for each EQ setup, since you're going to have to reproduce and save each one all over again whenever you do decide to upgrade your driver version.