OK so I've tried it on a different computer and still get the same error messages...
PS C:\Users\Fiona> set-executionpolicy remotesigned
Execution Policy Change
The execution policy helps protect you from scripts that you do not trust. Changing the execution policy might expose
you to the security risks described in the about_Execution_Policies help topic at
go.microsoft.com/fwlink. Do you want to change the execution policy?
[Y] Yes [N] No [S] Suspend [?] Help (default is "Y"): y
set-executionpolicy : Access to the registry key
'HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\PowerShell\1\ShellIds\Microsoft.PowerShell' is denied.
At line:1 char:1
+ set-executionpolicy remotesigned
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [Set-ExecutionPolicy], UnauthorizedAccessException
+ FullyQualifiedErrorId : System.UnauthorizedAccessException,Microsoft.PowerShell.Commands.SetExecutionPolicyComma
nd
PS C:\Users\Fiona> $cred = get-credential
cmdlet Get-Credential at command pipeline position 1
Supply values for the following parameters:
Credential
PS C:\Users\Fiona> $session = new-pssession -configurationname microsoft.exchange -connectionuri ps.outlook.com/powershe
ll -credential $cred -authentication basic -allowredirection
new-pssession : Relative URIs are not supported in the creation of remote sessions.
At line:1 char:12
+ $session = new-pssession -configurationname microsoft.exchange -connectionuri ps ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidArgument: (ps.outlook.com/powershell:Uri) [New-PSSession], NotSupportedException
+ FullyQualifiedErrorId : CreateRemoteRunspaceFailed,Microsoft.PowerShell.Commands.NewPSSessionCommand
PS C:\Users\Fiona>