Since version 126.96.36.199 we switched to SHA-2 algorithm for digital signature of our kernel driver. If you receive this message in Windows 7, then your system is probably not properly updated. Specifically, you need this Windows update to make SHA-2 signatures work.
The other option is to disable driver signature enforcement, which we don’t recommend. It is also possible to use version 188.8.131.52 or any older release.
Note: On some systems you will be able to install NetLimiter 4, but the driver will not start after system restart and you will receive an error:
There was no endpoint listening at net.pipe://127.0.0.1/NetLimiterPipe0 that could....