powershell - How to install KVM on Windows server 2008 R2 -

When I run the following powershell command, I get an error.

The command is:

@powershell -nprofile-excigation policy unrestricted - comma "isx ((new object net.vibillion). Download string ('https: // raw .githubusercontent.com / aspnet / Home / Master / KVMMTLS1 ')) "

and the error is:

" 1 "argument (s) ) With "DownloadString" calling exception: "The request was aborted: SSL / TLS could not be made a secure channel." In line: 1 character: 1+ means ((new-object net.vibelant). DownloadString ('https://raw.githubusercontent.co ... + ~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~ + Category information: Not specified: (:) [], Law Invocation Exception + Fully Qualified Irride: WebExation

This command works fine on Windows 10.