And I assume you're uninstalling through control panel or an uninstall wizard? It's been a while since I uninstalled Arc on my home computer, but I talked to tech support and was given a list of folder paths to check to make sure everything got removed, and I did find some things hanging around after the uninstall. Might not be a bad idea to also do a search on This PC for things like ESRI, ArcGIS, Python, etc and see what may be there still. Here is the list they gave me:
C:\Program Files (x86)\Esri
C:\Program Files (x86)\Common Files\ArcGIS
C:\Program Files (x86)\Common Files\Esri
C:\Program Files\ArcGIS
C:\Program Files\Esri
C:\Program Files\Common Files\ArcGIS
C:\Program Files\Common Files\Esri
C:\Program Data\Esri
C:\Program Data\ArcGIS
C:\Program Data\FLEXnet
C:\Users\<USERNAME>\AppData\Local\ESRI
C:\Users\<USERNAME>\AppData\Local\ArcGIS
C:\Users\<USERNAME>\AppData\Roaming\ESRI
C:\Users\<USERNAME>\AppData\Roaming\ArcGIS