According to your description, I suggest you refer to the following information:

The machine prompt "unsigned 64-bit device driver installation is not supported" is mainly to ensure that the driver is complete, and the driver will not integrate malicious code disguised as legal content. This problem is usually caused by the fact that the driver you installed for the machine is not the officially downloaded driver or the operating system you installed yourself. I suggest you do the following to see if you can solve this problem:

1. Download the latest driver of this machine from official website website and reinstall it;

Note: Because there are many models under the Envy 4 series, the drivers will be different according to different models, so we can't provide you with the official drivers suitable for your machine. You can find the driver suitable for your machine according to the following official documents:

/chatAsk an online engineer to help you solve the problem further.

More product information is available in www.hp.com.cn/800..