Stop execution of PowerShell script and return to original batch file

You could work with exitcodes and change your scripts like this:

The PowerShell Script:

foreach ($script in $ScriptsHome) {
    $ProgressBar.Increment(1)
    $MessagesLabel.Text = $Messages[$ProgressBar.Value - 1]
    $process = Start-Process $script.FullName -Wait -WindowStyle Hidden -passthru
    if($process.ExitCode -ne 0){break}
}

The Batch Script:

:error
cscript %base_dir%\fail.vbs > %Log%
Exit /b 1

Exit will quit from Powershell. So, if you are running interactively, this is unexpected. Use Return instead, to stop executing the remaining lines of codes:

For ($i=0; $i -lt 5; $i++){
    Write-Host
    $input = $(Read-Host "Enter a number between 1 and 5")

    If ($input -In (1..5)){
        $MyIntNum = $input -as [int]
        Break
    }ElseIf($input -eq '0'){
        Return 
    }
    Else{
        Write-Host 'Please try again ...'
    }
}

Write-Host
Write-Host "You entered $input"

Output when you enter any number other than 0:

Enter a number between 1 and 5: 9
Please try again ...

Enter a number between 1 and 5: 7
Please try again ...

Enter a number between 1 and 5: 4

You entered 4

Result when you enter 0:

Enter a number between 1 and 5: 0

The general approach is to exit from the batch scripts with a non-zero exit code in case of an error and check the exit status in the PowerShell code, as @A189198 already showed in his answer.

I would, however, drop the VBScript entirely (you can display message boxes from PowerShell too), and capturing a Process object also isn't required since PowerShell automatically provides the information via the automatic variable $LastExitCode.

Change the error handling in your batch code to something like this:

if %errorlevel% neq 0 exit /b 1

and change this foreach loop:

foreach ($script in $ScriptsHome) {
    $ProgressBar.Increment(1)
    $MessagesLabel.Text = $Messages[$ProgressBar.Value - 1]
    Start-Process $script.FullName -Wait -WindowStyle Hidden
}
$Form.Dispose()

to this:

foreach ($script in $ScriptsHome) {
    $ProgressBar.Increment(1)
    $MessagesLabel.Text = $Messages[$ProgressBar.Value - 1]
    Start-Process $script.FullName -Wait -WindowStyle Hidden
    if ($LastExitCode -ne 0) {
        [Windows.Forms.MessageBox]::Show("Installation Fail!`nMessage1`nClick OK to Exit", 'Fail', 0, 'Error')
        break
    }
}
$Form.Dispose()

Thanks for every one for showing me the way to do it.I have found the solution. I have changed the foreach loop in the powershell script from

foreach ($script in $ScriptsHome) {
    $ProgressBar.Increment(1)
    $MessagesLabel.Text = $Messages[$ProgressBar.Value - 1]
    Start-Process $script.FullName -Wait -WindowStyle Hidden
}
$Form.Dispose()

to

foreach ($script in $ScriptsHome) {
        $ProgressBar.Increment(1)
        $MessagesLabel.Text = $Messages[$ProgressBar.Value - 1]
        #$Label.Text     = "$($script.Name)"   
        Start-Process $script.FullName -Wait -WindowStyle Hidden

        if (Select-String -Path C:\exitloop.txt "fail") 
        {
         break 
        } else {continue
        }
        }
    $Form.Dispose()

and in the ScriptInstall folder where there are 10 batch and vbs scripts in the batch scripts i have changed the code to.

:error
cscript %base_dir%\fail.vbs > %Log%
echo fail > c:\exitloop.txt
exit
:match
findstr /I /c:"xxxx" c:\match.txt
if %errorlevel% == 0 (
    goto nextStep
) else (
    goto ErrorCheck
)

so whenever there is a condition failure in the batch file the batch file will generate a txt file with text "fail" this happens before termination of that particular batch file. Immediately after that the control will go back to the powershell script which will check if "fail" exist in c:\exitloop.txt if yes this will stop the execution of the powershell script itself else it will continue calling the batch and vbs files. Thanks