Hi,
You should only have to use the Custom scan once and I hope your not using this machine while the custom scan is working ?
After that the Threat scan are good enough,
Personally I run the custom scan once every couple of weeks,
Once you get some clear scans,
Re-open Adcleaner and click on Uninstall button,
Re-download it,
This time to your Desktop

Or from the downloads folder/ Right click it and click on Properties,
General section,
See if there's a Unblock button active/ click on it apply and okay.
Drag the file to your desktop
Run as admin and scan again,
Post the scan results,
If it's fairly clean,
Reset your Browsers again, be sure to check the box to Delete personal settings in ie11,
Review your Uninstall a program list for anything odd,
Report back,
take screen shots of your uninstall a program list,
Cheers.