Maybe you could try the following.
Note: Paths may vary according to operating system. Also uninstall any third-party GIS programs that you may have installed.
Rename or delete following folders:
Rename: C:\Program Files (x86)\ArcGIS
Rename: C:\Program Files (x86)\Esri
Rename: C:\Program Files (x86)\Common Files\ArcGIS
Rename: C:\Program Files (x86)\Common Files\Esri
Rename: C:\Program Files\ArcGIS
Rename: C:\Program Files\Esri
Rename: C:\Program Files\Common Files\ArcGIS
Rename: C:\Program Files\Common Files\Esri
Rename: C:\Program Data\Esri
Rename: C:\Program Data\ArcGIS
Rename: C:\Program Data\FLEXnet
Rename: C:\Users\<USERNAME>\AppData\Local\ESRI
Rename: C:\Users\<USERNAME>\AppData\Local\ArcGIS
Rename: C:\Users\<USERNAME>\AppData\Roaming\ESRI
Rename: C:\Users\<USERNAME>\AppData\Roaming\ArcGIS
Rename: C:\ProgramData\Microsoft\Windows\Start Menu\Programs\ArcGIS
Rename: C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Esri
Go to regedit and rename/delete the following (if they exist):
Rename/Delete HKEY_LOCAL_MACHINE\SOFTWARE\ESRI
Rename/Delete HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\ESRI
Rename/Delete HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Flex LM License Manager
Rename/Delete HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\<Delete Any Folder that contains ArcGIS or Esri>
Rename/Delete HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\ArcGIS Server
Rename/Delete HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\<Delete Any Folder that contains ArcGIS or Esri within>
Rename/Delete HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\FLEXnet Licensing Service
Rename/Delete HKEY_CLASSES_ROOT\Installer\Products\<Delete Any Folder that contains ArcGIS or Esri within>
Rename/Delete HKEY_CLASSES_ROOT\Installer\Assemblies\<Delete Any Folder that contains ArcGIS or Esri within>
Rename/Delete HKEY_CLASSES_ROOT\<Delete and Folder that contains ArcGIS or Esri within>
Rename/Delete HKEY_CLASSES_ROOT\Installer\Assemblies\Global\<Delete all Keys beginning with ESRI or ArcGIS>
Reboot your system before installing the new product.
Think Location