Too many people are hung up on doing clean installs. There are times where its appropriate which is always due to a user error. Either monkeying with settings in the OS, dorking around with the registry etc. The only other thing that is also user realted but has nothing to do with laptops as they are not capable is when you push a overclock on the BCLK too far and corrupt the data on the OS drive.
Some programs are stubborn to uninstall, its not the fault of the OS but the program itself and often again back to user error. I dont know how deep you are into it now.
Most software that is worth having will have no issues uninstalling as developers took the time to write the uninstall correctly. However you will find that even the good ones still leave orphans behind after an uninstall not only files and folders but registry entries. In your case I would pretty much guarantee the reason you are getting the error that it is already installed when attempting to install the newest version is orphaned registry entries. The install looks to the registry as some of the things it does like turbo mode could wreak havoc if you have two installations working against each other and the software is not written to auto update.
Ive had zero issues with it on a G752VY that is still running on the original factory image. Immediately after getting any laptop I clone the orginal drive to a new drive and take out the OEM and put it away for safe keeping in case I need to send the machine in for service or as a back up of the original install with all the software and drivers.
One tool that is invaluable is Ccleaner. So much so that I bought a license for it.
https://www.piriform.com/ccleaner/downloadI use Ccleaner to do the uninstalls, it does a better job and lets you uninstall bloatware that doesnt even show up in the windows apps list for uninstall or anything else.
Once uninstall is complete check your programs folder for any orphaned folders or files and delete them, Usually this doesnt happenw ith Ccleaner but does 100% with windows.
Now go back to Ccleaner and run the registry cleaner tool that will remove all the orphaned entries there. You can save a back up of the registry is you are worried, it gives you a prompt.
When finished, reboot then install your updated version of gaming center that is available on the ASUS support web page.
“Two things are infinite: the universe and human stupidity, I'm not sure about the former” ~ Albert Einstein