Windows 10: How to get permission from TrustedInstaller to delete program files?

How do you get permission from TrustedInstaller so that you can delete program files that are protected by it?Or should you not delete such files?

:)

 

TrustedInstaller permissions

I am not introducing a third party between me and my PC. An explanation as to why you can't change permissions back to TrustedInstaller would be nice though. Its the only ownership that can be changed one way. And, is SYSTEM a good substitute for TrustedInstaller? Does this cause a trouble in my PC?

 

TrustedInstaller permissions

I changed permissions and ownership on a folder in order to delete subfolders. The original owner was TrustedInstaller. Once I deleted said files I tried to change ownership back to TrustedInstaller but it wouldn't take ownership. So, I changed ownership to SYSTEM, but I'm nervous this will cause a malfunction.

 

Can't delete files

I'm trying to delete a directory of old files (programs and Windows8 files) and get messages "Need permission from TrustedInstaller" and "Need permission from SYSTEM". I have the same problem if I try to delete sub-directories or individual programs. I tried
unsuccessfully to run TrustedInstaller as administrator (nothing happened).

These files are programs and program data from obsolete programs such as Window NT, Window Defender, etc.

How do I get these permissions?

DaveM, thanks for the suggestion to use Disk Cleanup. However this did not delete the files.