Typescript Run Command Error cannot be loaded because running scripts

Question

In typescript when i try to run typescript command

tsc First.ts

Then it's Give me Error 

File C:\Users\user\AppData\Roaming\npm\tsc.ps1 cannot be loaded because running scripts is disabled on this system.  

 

When i google then google suggest me this Command

 

Set-ExecutionPolicy -ExecutionPolicy RemoteSigned 

 

but its also give  

'Set-ExecutionPolicy' is not recognized as an internal or external command,

operable program or batch file.

 

please help me out.