PowerShell – Ultimate Oracle Client Deinstaller

I’ve put together a PowerShell deinstall script for Oracle clients that I’m dubbing the Ultimate Oracle Client Deinstaller. This deinstall script clears relevant environment variables and creates a .RSP file using Oracle’s deinstall.bat utility. It then deinstalls the Oracle client and cleans up the registry.

But wait, there’s more! This script is compatible with Oracle clients 11g, 12c, and 19c. It is even capable of removing multiple Oracle client instances from the same device – even if they’re sharing the same home.

#= ULTIMATE ORACLE CLIENT DEINSTALLER ===========================================================================
# Script written by Payton Flint
# See https://paytonflint.com/powershell-ultimate-oracle-client-deinstaller/
# Deinstalls 11g, 12c, 19c Oracle clients

# Function to set environment variables for all levels
function Set-EnvVar {
    param (
        $EnvVarName,
        $EnvVarValue
    )
    [System.Environment]::SetEnvironmentVariable($EnvVarName,$EnvVarValue,[System.EnvironmentVariableTarget]::Machine)
    [System.Environment]::SetEnvironmentVariable($EnvVarName,$EnvVarValue,[System.EnvironmentVariableTarget]::User)
    [System.Environment]::SetEnvironmentVariable($EnvVarName,$EnvVarValue,[System.EnvironmentVariableTarget]::Process)
}
# Refresh Environment Variables Function
Function Refresh-Env{
    # Clear nullified environment variables
    $machineValues = [Environment]::GetEnvironmentVariables('Machine')
    $userValues    = [Environment]::GetEnvironmentVariables('User')
    $processValues = [Environment]::GetEnvironmentVariables('Process')
    # Identify the entire list of environment variable names first
    $envVarNames = ($machineValues.Keys + $userValues.Keys + 'PSModulePath') | Sort-Object | Select-Object -Unique
    # Lastly remove the environment variables that no longer exist
    foreach ($envVarName in $processValues.Keys | Where-Object {$envVarNames -like $null}) {
    Remove-Item -LiteralPath "env:${envVarName}" -Force
    }

    # Update variables
    foreach($level in "Machine","User","Process") {
    [Environment]::GetEnvironmentVariables($level)
    }
}

# Use Set-EnvVar function to clear environment variables
Set-EnvVar -EnvVarName "TNS_Admin"     -EnvVarValue "$null"
Set-EnvVar -EnvVarName "_JAVA_OPTIONS" -EnvVarValue "$null"
Set-EnvVar -EnvVarName "ORACLE_HOME"   -EnvVarValue "$null"

# Execute Refresh-Env function
Refresh-Env

# Deinstall-Oracle Function
Function Deinstall-Oracle {

    # Look for "Oracle" directory on system drive
    $OracleDir = dir -Path "$env:SystemDrive\Oracle*" | Select -ExpandProperty "FullName"

    # If Oracle directory is present...
    if ($OracleDir -ne $null){
        
        # For each "Oracle" directory instance
        ForEach ($instance in $OracleDir) { 

            # If Deinstall_Oracle directory does not exist, create it
            $Deinstall_Oracle = "$env:SystemDrive\Deinstall_Oracle\"
            If (!(Test-Path $Deinstall_Oracle)){
                New-Item -Path "$Deinstall_Oracle" -ItemType Directory -Force
            }

            # Product path
            $ProductPath = Join-Path $instance '\product'

            # Get version number directory
            $VersionPath = dir -Path $ProductPath -Filter '*.*.*' -Recurse | Where-Object {$_.PSIsContainer -eq $True -and $_.FullName -notlike '*client*'} | Select -ExpandProperty "FullName"

            # For each deinstall directory instance within Oracle directory instance...
            ForEach ($version in $VersionPath) {
                
                # Get version number
                $VersionLeaf = Split-Path $version -Leaf

                # Check for deinstall directory instances within version number directory
                $DeinstallDir = dir -Path $version -Filter 'deinstall' -Recurse | Where-Object {$_.PSIsContainer -eq $True -and $_.FullName -notlike '*inventory*'} | Select -ExpandProperty "FullName"

                # Get Deinstall.bat path and filter alternative locations
                $DeinstallBatch = dir -Path $DeinstallDir -Filter 'deinstall.bat' | Where-Object {$_ -notlike '*inventory*'} | Select -ExpandProperty "FullName"

                # If Deinstall.bat exists...
                If ($DeinstallBatch -ne $null) {

                    # Create subdirectory in Deinstall_Oracle directory
                    $subDir = Join-Path $Deinstall_Oracle $VersionLeaf
                    New-Item -Path $subDir -ItemType Directory -Force

                    # Create .RSP file in subdirectory using deinstall.bat
                    Start-Process -FilePath "$DeinstallBatch" -Wait -NoNewWindow -ArgumentList "-silent -checkonly -o $subDir"

                    # Execute deinstall.bat using .RSP file
                    $RSP = Join-Path $subDir '\deinstall*.rsp'
                    Start-Process -FilePath "$DeinstallBatch" -Wait -NoNewWindow -ArgumentList "-silent -paramfile $RSP"
                }
            }
        # Remove Oracle* directory instances
        Remove-Item -Path $instance -Force -Recurse -ErrorAction SilentlyContinue
        }
    # Remove Deinstall_Oracle directory
    Remove-Item -Path $Deinstall_Oracle -Force -Recurse -ErrorAction SilentlyContinue
    }
} # End of Deinstall-Oracle function

# Clean up Registry Function
Function Remove-RegKey {
    param (
        $Reg
    )
    $Reg = $Reg
    Remove-Item -Path "Registry::$Reg" -Force -Recurse
}

# Call Registry Function
Remove-RegKey -Reg "HKEY_LOCAL_MACHINE/SOFTWARE/Oracle*"
Remove-RegKey -Reg "HKEY_LOCAL_MACHINE/SOFTWARE/Wow6432Node/Oracle*"
Remove-RegKey -Reg "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Oracle*"

# Call Deinstall-Oracle function
Deinstall-Oracle