The user who is using CA PAM client needs to have "Full Permission" to the location where CA PAM client is installed on the users host.
The write permission would allow the download of the required files and upgrade the CA PAM client to the CA PAM server level.
The files that are downloaded are .jar files.
There are no registry keys updates involved in upgrade of CA PAM client.
The full permissions are required for the user account that would be executing the CA PAM client.