As far as i can see during the winpkflt installer there is some reading and writing of registry keys done. Is there any need for particular registry settings for getting the drivers working?
These registry operations are done by DriverSigning utility which disables WHQL signature requirement if this is enabled. This is actual for Windows XP/2003 and allows to avoid unnecessary warnings.
But installing the drivers with the snetcfg.exe does not work for me 🙁
If installer does install successfully but you can’t do the same when calling snetcfg manually then may be this is about privileges your command line has? Try to start CMD as administrator.