virtualenv activate.ps1 hash error

[po20]

Hello

I try to work with a virtual environment under windows

I'm using Python 3.6, installed on c:\Python36-32 and everything I do as a command runs from the PowerShell console running as administrator.

> I created a project folder located on c:\myProject and a folder for the environment ; mkdir virtenv.

> Then I launched virtualenv .\Virtenv -> OK.

> Then I run the order .\virtenv\scripts\activate.ps1 -> ExecutionPolicy block the script
> Set-ExecutionPolicy AllSigned and then .\virtenv\scripts\activate.ps1 -> Error "the hash of the file did not match the signature"


>if I download the original archive https://pypi.python.org/pypi/virtualenv and replace activate.ps1 I get the same error
>if I remove the security (set-executionpolicy remotesigned) everything works, the environment is activated well.

Is it normal that the the official archive file hash is not good?
how can I avoid blowing up security?

Thanks you in advance