SQL Server Cleanup Using UninstallString When Programs and Features Entry is Missing

Issue

In some environments, SQL Server services may still exist on the server, but the related SQL Server entries are missing from Programs and Features. This can happen due to missing or corrupted registry entries, incomplete uninstallations, or failed patching activities.

To identify the uninstall information from the registry, the following PowerShell script can be used:

Get-ItemProperty HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\*, `
HKLM:\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall\* |
Where-Object { $_.DisplayName -like “*SQL Server 2016*” } |
Select-Object DisplayName, UninstallString

Solution

The above script helps retrieve the UninstallString for SQL Server components directly from the registry.

In many cases, the uninstall command may contain:

/I

For uninstallation, this should be replaced with:

/X

Example:

MsiExec.exe /x

This forces the uninstall operation instead of launching the installer in maintenance mode.


Important Remarks

  • This approach should mainly be considered for remote support cases or emergency cleanup situations.
  • There is always a possibility of future issues when manually cleaning up SQL Server components using registry-based uninstall methods.
  • The recommended and safest approach is always to rebuild the server if SQL Server installation metadata or registry entries are heavily corrupted.
  • Use this method only as a last resort and proceed at your own risk.

Summary

When SQL Server entries are missing from Programs and Features, the uninstall details can still be retrieved from the Windows registry using PowerShell. Replacing /I with /X in the uninstall command can help remove orphaned SQL Server components. However, since this method relies on registry-based cleanup, it should only be used cautiously in exceptional scenarios, with server rebuild remaining the preferred long-term solution.

Thank You,
Vivek Janakiraman

Disclaimer:
The views expressed on this blog are mine alone and do not reflect the views of my company or anyone else. All postings on this blog are provided “AS IS” with no warranties, and confers no rights.

Connect to SQL Server with PowerShell and Azure key Vault

-> Requirement will be to query an Azure SQL Database via PowerShell and display the results. We will not list the SQL Server Instance, Username and password as clear text in PowerShell script, instead we use the secret from Azure Key Vault to achieve this.

Create an Azure SQL Database

-> Complete tabs “Networking”, “Security”, “Additional settings” and “Tags” as appropriate.

Create an Azure Key Vault

-> Complete tabs “Access policy”, “Networking” and “Tags” as appropriate.

-> Get into Azure Key Vault “sqlcon-key-vault-eastus”. Click on “Secrets” and then “Generate/Import”,

-> Value as mentioned in above screenshot is as below,

Server=tcp:jbdw.database.windows.net,1433;Initial Catalog=prod-jbsqldb01;Persist Security Info=False;User ID=<username>;Password=<Password>;MultipleActiveResultSets=False;Encrypt=True;TrustServerCertificate=False;Connection Timeout=30;

-> Click Create.

Get the required Data using PowerShell

##Script to display database names available## 
## Version 1.0 
##Author : Vivek Janakiraman## 
##cls ##Clearing Screen 

Connect-AzAccount

##Key in the correct Subscription below##
Set-AzContext -Subscription "00000000-0000-0000-0000-000000000000"

$keyvault = "sqlcon-key-vault-eastus" ##Provide the Azure key Vault name##
$ConnectionString = "prod-jbsqldb01-connection-string" ##Provide the the name of the secret created within Azure key Vault##


$Vault = get-azkeyvault -VaultName $keyvault
$Secret = get-azkeyvaultsecret -Name $ConnectionString -VaultName $keyvault
$SecretValue = $Secret.SecretValue 
$ConnectionString = [System.Runtime.InteropServices.Marshal]::PtrToStringAuto([System.Runtime.InteropServices.Marshal]::SecureStringToBSTR($SecretValue))

$tsqlcommand = "select name from sys.databases"; 

#SQL Connection - connection to SQL server 
$sqlConnection = new-object System.Data.SqlClient.SqlConnection; 
$sqlConnection.ConnectionString = $connectionString; 

#SQL Command - set up the SQL call 
$sqlCommand = New-Object System.Data.SqlClient.SqlCommand; 
$sqlCommand.Connection = $sqlConnection; 
$sqlCommand.CommandText = $tsqlcommand; 

#SQL Adapter - get the results using the SQL Command 
$sqlAdapter = new-object System.Data.SqlClient.SqlDataAdapter 
$sqlAdapter.SelectCommand = $sqlCommand 
$dataSet = new-object System.Data.Dataset 
$recordCount = $sqlAdapter.Fill($dataSet) 

#Close SQL Connection 
$sqlConnection.Close(); 

#Get single table from dataset 
$data = $dataSet.Tables[0] 
$data

-> Below is the output,

-> There is a possibility of below error while executing the script,

Exception calling "SecureStringToBSTR" with "1" argument(s): "Value cannot be null.
Parameter name: s"
At C:\temp\Connection_Template_Working.ps1:16 char:1
+ $ConnectionString = [System.Runtime.InteropServices.Marshal]::PtrToSt ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : ArgumentNullException
 
Exception setting "ConnectionString": "Format of the initialization string does not conform to specification starting at index 0."
At C:\temp\Connection_Template_Working.ps1:22 char:1
+ $sqlConnection.ConnectionString = $connectionString;
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], SetValueInvocationException
    + FullyQualifiedErrorId : ExceptionWhenSetting
 
Exception calling "Fill" with "1" argument(s): "The ConnectionString property has not been initialized."
At C:\temp\Connection_Template_Working.ps1:33 char:1
+ $recordCount = $sqlAdapter.Fill($dataSet)
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : InvalidOperationException

Exception calling “SecureStringToBSTR” with “1” argument(s): “Value cannot be null.

-> This error occurs when parameter $ConnectionString is wrong. It should be same as what is seen in below screenshot in Azure key Vault,

Thank You,
Vivek Janakiraman

Disclaimer:
The views expressed on this blog are mine alone and do not reflect the views of my company or anyone else. All postings on this blog are provided “AS IS” with no warranties, and confers no rights.