RéglageHOMEACCUEIL dans PowerShell

Comment changer mon répertoire personnel par défaut en "C:Userskhornsby "pour chaque fois que j'ouvre powershell?

J'exécute Windows 7. Vous trouverez ci-dessous des informations sur l'état de mon environnement.

Windows PowerShell
Copyright (C) 2009 Microsoft Corporation. All rights reserved.

PS P:> cd ~
PS P:> echo $HOME
P:
PS P:> HOME="C:Userskhornsby"
The term 'HOME=C:Userskhornsby' is not recognized as the name of a cmdlet,
function, script file, or operable program. Check the spelling of the name, or
if a path was included, verify that the path is correct and try again.
At line:1 char:25
+ HOME="C:Userskhornsby" 

PS P:> Set-Variable HOME "C:Userskhornsby"
Set-Variable : Cannot overwrite variable HOME because it is read-only or
constant.
At line:1 char:13
+ Set-Variable 

PS P:> dir env:home*

Name                           Value
----                           -----
HOMEPATH                       
HOMEDRIVE                      P:
HOMESHARE                      \fileservkhornsby$


PS P:>