How can I determine if SQL Server Management Studio Express (2005) is installed?

I need a way to determine from Wise Install Script if SQL Server Management Studio Express 2005 is installed on computer. Does someone know a Registry entry or something that will be present when SSMSE is installed?

From stackoverflow

• You could try this:

  HKEY_LOCAL_MACHINE\Software\MSSQLServer\MSSQLServer\CurrentVersion
  

  Get the value of CurrentVersion key and compare it with the version of SQL Server Management Studio Express 2005.

  stephbu : I wouldn't recommend this - this key can also indicate that only the service is installed.

• Most reliable way to detect it would be to use the MSI database to detect the state of SQL Server Management Studio.

  There is a COM object you can use to query the MSI database:

  http://msdn.microsoft.com/en-us/library/aa369432.aspx

  the Installer.Products property can tell you what products/packages are installed. Installer.ProductState can tell you the state of the product/package.

  Most installer systems can also do the same checks - either use the API, Orca or similar MSI tool to find the product SQL Mgmt Studio Package/Product ID.