Looks like its driver is quite limited in capabilities and ignores documentation. It's a file system driver, so it emulates file system access. But it doesn't support all the queries the standard driver supports. For example GetFinalPathNameByHandle API flag FILE_NAME_NORMALIZED isn't handled at all. And FILE_NAME_OPENED flag only supports VOLUME_NAME_NT flag, but filename returned isn't accepted by CreateFile. Or QueryFullProcessImageName with 0 flag is supposed to return Win32 path format, but it returns native system path format. So it's definitely not ReHIPS bug, but I'll take a look, maybe I'll be able to find some workarounds.