Modifying Explorer.exe Graphics

This be my first thread, but it's been the first major modification attempt I've decided on in the Windows 7 beta.

I was playing around with XN Resource Editor, a useful tool for editing some of the graphics contained in EXEs. I found out that the start button is stored in Explorer.exe, which was not much a surprise. However, the surprise came when I tried to replace Explorer.exe with a modified file. The issue is not that it's modified, it's that I can't touch it.
I've already attempted renaming the file (both XP and 7), but it's completely locked due to NTFS. I even tried the XP Recovery Console, but it wants an administrator password that doesn't exist.

The only two major clues I have is that, when attempting to edit it in 7, it says "Only changable from "TrustedInstaller" source, which I'm assuming would be a Microsoft update, and that in other instances the file comes up with "Access is denied. It is either unaccessible or write-protected".

So, anyone else have an idea of how to shift this file around? I know it seems kinda useless, if only to edit a few graphics, but at the same time it's showcasing some major protection against malware.

Thanks in advance!

Yup - take ownership of the file.

In Vista and *especially* in W7, Administrative privileges are not the *highest* allowed. TrustedInstaller is the end all be all for installation of programs, and NT_SYSTEM is the end all be all for your system.

You need to take ownership of explorer.exe so you can replace it, and I am betting that after that you'll also have to kill it in Task manager or Process Explorer.

Thank you Johngalt, seriously.

I admit, I used XP for at least 6 years and never did work with Vista, so I was unaware file owner played a huge part in file modification. Thanks to that tip and some googling, looks like my start button editing can work now.

EDIT: It looks like even after editing all possible Bitmaps, the startbutton has not changed a bit, so this method is rather pointless. That or Explorer is being automatically reverted after I change it, also possible thanks to the automatic system file repairing Windows did (I was aware of this in the past).

EDIT2: I updated the file through XP after taking ownership, and it still did nothing, so I'm wondering if XN Resource Editor can't handle these files yet. Even after such progress of replacing it, it doesn't do anything, so I'm about a step away from not caring anymore.

Or it could be that after you replace it it is automatically being re-replaced?

Have you replaced the file and then opened it back up to see if your changes are still there?