You may compare with another machine where SEP is also installed, to identify files that you may/may not delete. The best would probably be to simply uninstall SEP client, purge these folders, then reinstall SEP.
By the way, you should be able to delete Cached Install content if you are connected as admin and if Tamper protection is disabled. To disable Tamper Protection via SEPM, please follow these steps:
- Open Symantec Endpoint Protection 12.1
- Click on "Change Settings"
- Next to Client Management, click on "Configure Settings"
- Select the "Tamper Protection" tab
- Un-check "Protect Symantec security software from being tampered with or shut down"
- Click on OK
- Close Symantec Endpoint Protection 12.1
(source: http://www.symantec.com/docs/TECH166129)
To disable Tamper Protection locally via Client GUI, open the SEP 12.1 client, clickChange settings, click Configure Settings (next to Client Management), click Tamper Protection, remove the checkmark from "Protect Symantec security software from being tampered with or shut down", and click OK.
(source: http://www.symantec.com/docs/TECH104758)
You will need to find out as well why such files (not related to SEP) were backup there (backup solution in place? wrong system variable, for instance Cached Install folder defined as user temporary folder? any script?).