PowerShell SharePoint 2010 Backup

I need to schedule SharePoint 2010 Backup (site):
First create a PowerShell script in Notepad:
Backup-SPSite -Identity http://wss-08r2 -Path "\\servername\sharepoint2010\one\wss-08r2.bak" -Force

name the file - backup.ps1

Second:
Under folder C:\Windows\System32\WindowsPowerShell\v1.0 create profile.ps1 file it will be default profile for all users on the SharePoint front end server, edit the file by adding -

Add-PSSnapin Microsoft.SharePoint.PowerShell

And save the file.

Third:

Create a scheduled job and in Action tab put:

Action: powershell.exe

Add arguments: -command "PATH\backup.ps1"

where is PATH - path to the script file.