Scheduling a script performing database backup

Question

I wrote a script performing a backup of all databases located on a SQL Server's instance using the Backup-SqlDatabase command. As a script from the Windows Powershell ISE it works fine. I am working on a Windows Server 2012
The next step is to schedule this from the Windows Task Scheduler. The Action program is PowerShell and the arguments is -command "& 'C:\folder\myscript.ps1'" and it doesn't work, the script appears to fire off but it doesn't
perform the backup. The error looks strange it looks like it can't connect to the SQL Instance, I tried a whole bunch of options I found googling around but none worked. What am I missing ?

Answer 1

1) Using -File instead of -Command didn't work, it didn't even fire the script
2) I have got 'Run with the highest privileges' selected
3) The error
4) The script
# backup_AllDb.ps1
# Full backup for database for specified SQL instance
# Change log:
# July 3, 2012: Thomas LaRock, http://thomaslarock.com
# Initial Version
# Get the SQL Server instance name from the command line
# leaving $dest null will result in default backup path being used
param(
[string]$inst=$null,
[string]$dest=$null
# Load SMO assembly, and if we're running SQL 2008 DLLs load the SMOExtended and SQLWMIManagement libraries
$v = [System.Reflection.Assembly]::LoadWithPartialName( 'Microsoft.SqlServer.SMO')
if ((($v.FullName.Split(','))[1].Split('='))[1].Split('.')[0] -ne '9') {
[System.Reflection.Assembly]::LoadWithPartialName('Microsoft.SqlServer.SMOExtended') | out-null
[System.Reflection.Assembly]::LoadWithPartialName('Microsoft.SqlServer.SQLWMIManagement') | out-null
# Handle any errors that occur
Function Error_Handler {
Write-Host "Error Category: " + $error[0].CategoryInfo.Category
Write-Host " Error Object: " + $error[0].TargetObject
Write-Host " Error Message: " + $error[0].Exception.Message
Write-Host " Error Message: " + $error[0].FullyQualifiedErrorId
Trap {
# Handle the error
Error_Handler;
# End the script.
break
If ($inst -eq "")
{ $inst = "MYSERVERNAME\MYINSTANCE" };
$srv = new-object ('Microsoft.SqlServer.Management.Smo.Server') $inst
# If missing set default backup directory.
If ($dest -eq "")
{ $dest = "C:\SQLBackups" };
Write-Output ("Started at: " + (Get-Date -format yyyy-MM-dd-HH:mm:ss));
cd SQLSERVER:\SQL\$inst\Databases
#start full backups
foreach($database in (Get-ChildItem -Force)) {
$dbName = $database.Name
if ($dbName -ne "tempdb") {
$timestamp = Get-Date -Format MMddyyHHmm
$bakFile = $dest + "\" + $dbName + "_full_" + $timestamp + ".bak"
Backup-SqlDatabase -Database $dbName -Initialize -BackupFile $bakFile
Write-Output ("Finished at: " + (Get-Date -format yyyy-MM-dd-HH:mm:ss));