Some Windows 10 systems may experience an error when attempting to update or install Cisco Secure Client if a previous version of the software was present on the device.
 
Known Causes & Symptoms:
- User upgraded to windows 10 without uninstalling Secure Client first.

- The Cisco Secure Client automatic update failed to complete or was interrupted. 
- Cisco Secure Client Reinstall/Upgrade will not complete and will post error to event log.
 
There is a problem with this windows Installer package. A program run as part of the setup did not finish as expected. Contact your support personnel or package vendor"
 
Resolution:
 
These solutions have not been tested and should not be recommended for personal devices.
 
https://community.cisco.com/t5/vpn/anyconnect-re-install-on-windows-10-hanging/td-p/2703272
 
https://www.tecklyfe.com/cisco-anyconnect-fails-install-upgrade-windows-10-anniversary-update/