Problem with installing NuGet packages

I'm trying to install NuGet packages like Unity or EntityFramework, but after downloading Nuget cannot install those and returns this error message:

Your machine group policy or user group policy disables execution of PowerShell script.
Adjust your group开发者_C百科 policy settings to allow execution of PowerShell scripts

How can I resolve this issue? Thanks in advance ;)

Currently old version of NuGet aka not > 1.4 do not sign powershell scripts and thus you need to run the following from a powershell command line:

set-executionpolicy Unrestricted

in 1.4 we are going to sign the scripts so you shouldn't have this problem. Although 1.4 has not shipped yet, but very very soon :)

The above fix might fail if your administrator has locked down powershell scripts in that case you can either ask them to do this for you or wait till NuGet 1.4 is released.