[Win 2K] Replacing protected system files

I have an old DLL file - specifically ScrRun.dll - that I need to replace with the current version in %SystemRoot%\system32. Windows 2000 will let me do everything to the file, from delete it to overwrite it, but it always instantly puts the original (old) file in its place (a "feature" of Windows File Protection). This is beginning to piss me the fuck off, and Google gives me jack shit.

I tried the kill Explorer/paste via Task Manager method to no avail.

Suggestions?

Thanks.

boot into safe mode, delete that file, delete dllcache and then replace the file?

also: http://www.winguides.com/registry/display.php/790/ and http://www.google.com/search?sourceid=navclient&ie=UTF-8&oe=UTF-8&q=disable+Windows+File+Pr otection

Thanks. Kurayami reminded me that I needed to unregister the DLL first.

bloops. posted here before i saw the thread in general.