[RESOLVED] ERROR: The process cannot access the file . . .

[Muddy]

Well it's been a while. It's awesome to see this place still thriving after all of these years.
I've got an error I cannot figure out after much online searching. Ive tried all sorts of things but am at a loss.Hoping someone here can help. The error I am getting is this
mscorlib.dll
Additional information: The process cannot access the file 'C:\dbfile.mdf' because it is being used by another process.

I am using Visual Studio 2017 VB.net. My Imports are:

Imports System
Imports System.IO
Imports System.IO.Compression
Imports Microsoft.VisualBasic
Imports System.Data.OleDb
Imports System.Data
Imports System.Data.SqlClient

The offending code:

 ' NOTE THAT I EDITED THE FILENAME DOWN TO SOMETHING SIMPLE. IT ISNT REALLY IN THE ROOT DIR. 
'I HAVE FULL PERMISSIONS WHERE IT RESIDES AND CAN INDEED COPY/DELETE/ETC IT PROGRAMATICALLY WHERE IT RESIDES
           connectionString = "Data Source=(localdb)\v11.0;Integrated Security=true;AttachDBFileName="C:\dbfile.mdf"
                connection = New System.Data.SqlClient.SqlConnection(connectionString)
                connection.Open()
                    queryString = "SELECT * FROM dbo.myTable;"
                    adapter = New SqlDataAdapter(queryString, connection)
                adapter.UpdateCommand = New SqlCommandBuilder(adapter).GetUpdateCommand()

                runParams = New DataSet()
                    adapter.Fill(RunParams, "RunParams")
                    runParams.Tables(0).Rows(0).Item(3) = 1
                adapter.Update(runParams, "RunParams")

                connection.Close()

                adapter.UpdateCommand.Dispose()
                adapter.Dispose()
                    runParams.Dispose()


                connection.Dispose()
                'ALL WORKS PERFECT TO THIS POINT, BUT AFTER THIS POINT, IF I TRY TO DO ANYTHING WITH THE MDF FILE (COPY,MOVE, WHATEVER) I GET THE ERROR