I've installed Windows 7 x64 over a previous pre-release version. What typically happens is that if you choose not to format it moves everything in existing Windows folders (Program Files, Users etc) into a folder called Windows.old. Then it creates new Windows folders and assigns Admin/System/TrustedInstaller permissions to them so that a regular user can't go about messing with system files/installed applications.

I've done this several times before with previous versions but with version 7600 I've encountered a problem that prevents me from deleting/changing anything in those folders even though I'm an Administrator.

Eg. If I try to remove something from the Program Files folder, it tells me I need permissions from Trusted Installer.

If I change the owner of the file, I still get the error "You require permissions from [owner]". It definitely seems like a bug because even if I make myself the owner, I still get the error. I've found one way around this by removing inherited permissions, changing the owner and permissions and propagating the changes down to all the children (starting at the root). Sometimes it works for groups of folders, other times I have to do it individually per file. Either way, I don't think it's a good workaround because it requires me to make permission changes to entire folders, rather than just the files I wish to edit/remove.

Does anyone know of a fix to this problem?

[edit: Installing "over" a previous version is not the same as an "upgrade". None of your system settings/applications are preserved.]

  • Are you trying to delete something that came with Windows (i.e. Wordpad)? If so, this is by-design...
    – Ana Betts
    Aug 18, 2009 at 15:08
  • No, I'm trying to remove edit files associated with 3rd party applications that I've installed.
    – user5938
    Aug 18, 2009 at 15:17

2 Answers 2


What about using the Take Ownership registry hack http://v.be.sl.pt? I was able to get it working with the RC version of 7, and it helped me delete those artifacts of patch upgrades which don't let you have access.

  • I'll try that, but I've already tried changing the owner explicitly and it didn't work.
    – user5938
    Aug 18, 2009 at 15:18
  • +1: Nice hack....let me get rid of an old Windows 7 test install from my D: drive.
    – Kev
    Aug 25, 2009 at 9:30

I know this is lame but installing Windows 7 over previous builds of Windows 7 is not supported. This is typical of the problems that can be caused by this action.

  • This is what I don't understand though - I didn't install it "over" the previous installation. Windows doesn't allow you to do that. It moves all previous system files into a folder called "Windows.old" and then continues the installation as normal. None of the previous system files are referenced.
    – user5938
    Aug 18, 2009 at 14:42
  • It is still considered an upgrade however an not supported Aug 18, 2009 at 14:59
  • 1
    Diago: That's not true. to-tech.com/blog/2009/05/05/…
    – user5938
    Aug 18, 2009 at 15:09
  • It's considered a destructive upgrade ilitirit... Aug 18, 2009 at 16:41
  • By whom? I can't find any documentation about "Destructive Upgrades"...
    – user5938
    Aug 20, 2009 at 15:26

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