MrBill said:
A simple question, I think. I want to copy one of my screen savers
(.SCR) from my XP machine to my new Vista PC, but although I can see
the contents of the C:\Windows\System32\ folder, I cannot copy my
screensaver to it. Can anyone help?
Is there a writeup to explain about owners, administrators, etc. and
how to use these "features" for the novice?
Thanks, Bill
Hello,
- What tool are you using to do the copying?
- Is there a file with the same name already in \systm32?
1) Try using windows explorer to do the copying, if you aren't already.
In Windows, only programs that ask for your permission can use your
administrator power. Explorer knows how to do this correctly. It takes
admin power to put stuff in system32.
2) If there is an existing screen saver already there, Windows is
denying you access to modify it. This is part of Windows File Protection
- it keeps protected OS files from being modified by only allowing
trusted system components (such as windows update) to modify these files.
To gain access to the file to replace it, you will need to take
ownership of it and then give yourself permission to modify it (using
the security tab).
Security in windows can be complicated in practice, but the concept is
fairly simple.
- Every person who uses the computer has an account. They can be members
of "groups", such as the administrators group or the users group.
- Windows controls access to "securable objects" - these include files,
folders, and registry settings, among other things.
- Every securable object contains 1) an owner (can be a user account or
group) and 2) a list of accounts or groups who can access the object, as
well as how much access they have.
- When you access an object, windows checks the access list on the
object to see if you are on the list. If you are, you get whatever
access to the object that the object has for you on the list. If you're
not on the list or you are explicitly denied access, you are not allowed.
- Ownership on windows is hyped up more around here than it really
should be. It is primarily a tool used for auditing (i.e. who created a
file).
However, owning an object does grant you two special privileges: you can
both look at and modify the permission list for an object that you own,
even if the object does not explicitly grant you those privileges.
So, owning an object does NOT mean that you automatically have full
control over it. It only means that you can always see and edit the
access list for the object to give yourself full control, if you need to.
By default, administrators can take ownership of any object on the
system. This prevents objects from becoming completely unaccessible due
to misconfiguration or malice - an admin can always take ownership of an
object that they don't have access to and fix its permissions.
The general rule for administration in Windows is: anything that only
applies to a certain user account, is readable and writable by that user
account. Everything else is generally readable, but not writable.
It takes administrator power to write to files and settings that apply
to other users or the system in general.
This is complicated somewhat in Vista, where only applications that ask
("Windows needs your permission to continue") are allowed to use your
admin power.
This prompt is a good thing, though; it prevents programs that you don't
run from using your admin power against you.
Just remember, if you are wanting to do an admin action (anything that
could affect other users or the system), you will have to use a program
that prompts. If the program doesn't prompt, you will need to give it
special permission by right-clicking it and clicking run as administrator.
