The following error occurs while trying to upgrade WCC on Windows:
Could not get write access to WCC install folder D:\Program Files (x86)\CA\Workload Control Center, Backup folder was not created.
Fix the problem and select OK to try again. Select Cancel to abort

Product - WCC 11.4.x
Platform - Windows
 

Uninstall previous installed WCC
Delete Workload Control Center directory
(if Workload Control Center directory is not deleted automatically)
Download WCC media from support.ca.com
Use latest version of winiso for mounting the media
Clean up the Temp directory
Restart the System
Install the product making sure to use a right mouse click and select run as administrator when launching the install.