I would recommend leaving the
owner setting alone and left set to TrustedInstaller. Changing this on the C: drive will cause access denied issues with Vista.
There are a few essential protected system resources (system files, folders, and registry keys) that are installed as part of Vista. To help prevent a application and operating system failure, these resources are protected using Windows File Protection (WFP) in such way that applications or users cannot modify these resources by default. The way this protection is implemented is by setting an Access Control List (ACL) on these resources only to allow the
TrustedInstaller user to modify them. Not only can a
Administrator (elevated or not) account cannot modify them, but neither can the System.
By default a user will have full permission in their user account for their user folder files. Only the administrator has access permission for all files and folders on the computer. It is best to only grant users full permission of items that they would not normally have if it is needed.
When you grant
Users (Name-PC\Users) Full control, then anyone and any program running in that user account will have full control of the item you gave them access permission. This can pose a security risk if you allow full control to everyone and everything, since it will also allow malware to have full access as well.
It's best to leave these settings to default unless you just wanted to allow a individual user access to a single file or folder.