Uninstalled a program via PowerShell script, but it still shows up in Programs and Features

Question

I wrote a script that uninstalls a program just fine, but it still shows up in Programs and Features due to its entries still existing in the Registry. 
Here is a portion of my script:
Start-Process
-FilePath MsiExec
-ArgumentList "/X$($MyProgram.ProdID)",
'/quiet'
-NoNewWindow -Wait
-PassThru 
I believe the reason it is still showing up in Programs and Features is because I am missing some MsiExec switch to instruct it to be removed. I vaguely recall dealing with this about two years ago and I wrote a script that did exactly this, but now I completely
forgot what it was. 
Can someone help me out here, please?
Thank you

Answer 1

I realize that, but honestly don't know where else to submit a question like this in the forums? Also, the vendor is Microsoft. What I am trying to uninstall is any Forefront component, because when I deployed the SCEP client via SCCM 2012 the SCEP client
was not able to uninstall some of the Forefront components. 
Here is my script:
$NewLine = "`r`n"
$NewLine
Write-Output "Please wait ..."
#region ---------- Declare WMI Variables to be Used ----------
$CM12R2ClientInstalled = Get-WmiObject -Class Win32_Product |
Where-Object -FilterScript { $_.Name -eq "Configuration Manager Client" -and $_.Version -ge "5.00.7958.1000" }
$FCSInstalled = Get-WmiObject -Class Win32Reg_AddRemovePrograms |
Where-Object -FilterScript { $_.DisplayName -match "Forefront" }
$SCEPInstalled = Get-WmiObject -Class Win32Reg_AddRemovePrograms |
Where-Object -FilterScript { $_.DisplayName -eq "System Center Endpoint Protection" }
#endregion ---------- Declare Variables to be Used ----------
#region --------- Check if the SCCM 2012 R2 Client is Installed ---------
$CM12ClientService = Get-Service -Name CcmExec
If (($CM12R2ClientInstalled -ne $null) -and ($CM12ClientService -ne $null))
$NewLine
Write-Output "The $($CM12R2ClientInstalled.Name) $($CM12R2ClientInstalled.Version) is installed on $($env:COMPUTERNAME)"
#endregion --------- Check if the SCCM 2012 R2 Client is Installed ---------
#region -------- Uninstall any Forefront Component if any are Installed ---------
If ($FCSInstalled)
$NewLine
Write-Output "The following Forefront component(s) are installed on $($env:COMPUTERNAME):"
$NewLine
$FCSInstalled.DisplayName
Foreach ($FCS in $FCSInstalled)
$NewLine
Write-Output "Preparing to uninstall $($FCS.DisplayName)"
$UninstallFCS = Start-Process -FilePath MsiExec -ArgumentList "/X$($FCS.ProdID)", 'REMOVEDATA=1' -NoNewWindow -Wait -PassThru
If ($($UninstallFCS.ExitCode) -eq '0')
$NewLine
Write-Output "$($FCS.DisplayName) uninstalled successfully!"
$NewLine
#endregion -------- Uninstall any Forefront Component if any are Installed ---------
#region --------- Install the SCEP Client if it is Not Installed ----------
If ($SCEPInstalled -eq $null)
$NewLine
Write-Output "The System Center Endpoint Protection client is not installed on $($env:COMPUTERNAME)"
$InstallSCEP = Start-Process -FilePath "C:\Windows\ccmsetup\SCEPInstall.exe" -ArgumentList '/s', '/q', '/NoSigsUpdateAtInitialExp', '/policy "C:\Windows\CCM\EPAMPolicy.xml"' -NoNewWindow -Wait -PassThru
If ($($InstallSCEP.ExitCode) -eq '0')
$NewLine
Write-Output "System Center Endpoint Protection installed successfully!"
$NewLine
Else
$NewLine
Write-Warning -Message "System Center Endpoint Protection failed to install on $($env:COMPUTERNAME) with exit error: $($InstallSCEP.ExitCode)"
$NewLine
#endregion --------- Install the SCEP Client if it is Not Installed ----------
Else
$NewLine
Write-Output "The System Center Endpoint Protection client is already installed on $($env:COMPUTERNAME)!"
$NewLine
Else
$NewLine
Write-Warning -Message "$($FCS.DisplayName) failed to uninstall on $($env:COMPUTERNAME) with exit error: $($UninstallFCS.ExitCode)"
$NewLine
Else
$NewLine
Write-Output "No Forefront components are installed on $($env:COMPUTERNAME)!"
#region ---------- Install the SCEP Client if it is NOT Installed ----------
If ($SCEPInstalled -eq $null)
$NewLine
Write-Output "The System Center Endpoint Protection client is not installed on $($env:COMPUTERNAME)"
$InstallSCEP = Start-Process -FilePath "C:\Windows\ccmsetup\SCEPInstall.exe" -ArgumentList '/s', '/q', '/NoSigsUpdateAtInitialExp', '/policy "C:\Windows\CCM\EPAMPolicy.xml"' -NoNewWindow -Wait -PassThru
If ($($InstallSCEP.ExitCode) -eq '0')
$NewLine
Write-Output "System Center Endpoint Protection installed successfully!"
$NewLine
Else
$NewLine
Write-Warning -Message "System Center Endpoint Protection failed to install on $($env:COMPUTERNAME) with exit error: $($InstallSCEP.ExitCode)"
$NewLine
#endregion --------- Install the SCEP Client if it is Not Installed ----------
Else
$NewLine
Write-Output "The System Center Endpoint Protection client is already installed on $($env:COMPUTERNAME)!"
$NewLine
Else
$NewLine
Write-Output "The System Center Configuration Manager 2012 R2 client is not installed on $($env:COMPUTERNAME)!"
$NewLine