Firstly, was the only Asus product you have the motherboard or do you have an Asus video card? If it's just the motherboard then remove anything Asus related. If you have a video card (or something else from Asus) then confirm that it's related to the mobo before you remove it.
Depending on what you've installed previously you could have Asus AI suite, Armory Crate and Aura Creator. Look for those since they're the usual culprits.
Start with the obvious, Windows Settings - Apps. Looks for the above-mentioned Asus Apps and remove them.
It's possible Asus apps are installed that don't appear in settings-apps. If you check the start menu for Asus items do you see a folder for "Asus" or any of the three apps from above? If so look for an uninstall option in that. If you can't see an explicit uninstall option right click on the app in the start menu. You should see an option to uninstall in the pop-up menu.
If that doesn't help then let us know because it's probably going to get fiddly...
