So one of the new features listed in the TextPad 7 release notes is that 64bit redirection is disabled:
64-bit file system redirection is disabled so that files in 64-bit Windows folders can now be edited.
However it doesn't seem to work. I placed a file called "THIS IS THE SYSWOW64 DIR.TXT" in the C:\Windows\SysWOW64\inetsrv\Config directory, but when I try to open a file in C:\Windows\System32\inetsrv\Config, I see it instead of my normal IIS config files.
I know you can hack this by using \windows\sysNATIVE, but it seems that this should work.
Microsoft have not provided a mechanism to bypass file system redirection with the standard File Open/Save As dialog boxes. You can use Windows Explorer to pass files to TextPad, or use the Quick Open (Crtl+Shift+O) command instead. We'll update the release notes to make this clear.
As the comments on that article state, it doesn't work post Vista. The problem is that redirection can only be disabled by the calling thread, and the file open/save as dialog boxes create their own threads. They also load DLLs to handle virtual directories, so any tricks to prevent redirection could end up with the wrong DLLs being loaded.