Windows 7: Default Permissions and Ownership of C:\Windows and subcontainers

I had to change the owner and permissions of the C:\Windows folder in order to install a particular software. When I changed these settings, I had the "Replace owner on subcontainers and objects" box checked. Ever since I made these changes, most of my icons won't appear properly and several windows updates have failed. I figure its safe to say I made a mistake. Does anyone know how to return all ownership and permissions to default values without doing a full install of the OS? I tried creating a recovery disc and running a repair, but it didn't fix the issue. I also have no image to restore to.



I'm running 7 Home Premium 64bit.

Thanks.

Try system restore. If not when did you make your last backup. Try Backup as last resort.

I've done the same thing - taking ownership of the entire C:\Windows folder - and haven't had any issues since then.

I think the actual problem might be that you (intentionally or accidentally) changed permissions for the SYSTEM and TrustedInstaller "users" to access the contents of C:\Windows. (Remember ownership and permissions are separate things in Windows 7.)

I'm pretty sure that TrustedInstaller should have "full" access to everything whereas SYSTEM would have read/execute permissions only, but I'm not sure which files and folders this applies to exactly. (Obviously, SYSTEM would also need to have full access to some things in the Windows folder.)

So a "quick fix" would be to simply give full permissions to both of these entities, although this will unfortunately weaken security a little bit (meaning, any process running as SYSTEM gets full access, including malware or badly written apps).