Error in Version Control wizard pane when entering a Working Directory: "System.IO.FileNotFoundEx (4220259)

User is attempting to configure Visual SourceSafe with Toad. When attempting to enter working directory in Version Control wizard, the below error occurs:

"System.IO.FileNotFoundException
Retrieving the COM class factory for component with CLSID {783CD4E4-9D54-11CF-B8EE-00608CC9A71F} failed due to the following error: 8007007e.
Stack Trace:
at Quest.VersionControl.VSS.VSSProvider.Login(IProviderSetting settings)
at Quest.Toad.VersionControl.RepositoryManager.ValidateLogin()
at Quest.Toad.VersionControl.RepositoryManager.CheckLogin()
at Quest.Toad.VersionControl.RepositoryManager.SelectWorkingFolder(String workingFolder, String folder)..."