Software\Microsoft\Windows\CurrentVersion\Explorer\RunMRU

Use RegEnumValue to list the values and RegDeleteValue to delete them. Use RegCloseKey to close the key when you are finished. Then reboot.

Private Sub Command1_Click()
Dim hKey As Long
Dim value_name_len As Long
Dim value_name As String
Dim value_data(1 To 1024) As Byte
Dim value_data_len As Long
Dim value_type As Long
Dim value_data_string As String
Dim i As Integer

    ' Open the key.
    If RegOpenKeyEx(HKEY_CURRENT_USER, _
        "Software\Microsoft\Windows\CurrentVersion\Explorer\RunMRU", _
            _
        0&, KEY_ALL_ACCESS, hKey) <> ERROR_SUCCESS _
    Then
        MsgBox "Error opening key."
        Exit Sub
    End If

    ' Delete the key's values.
    Do
        value_name_len = 1024
        value_name = Space$(value_name_len)
        value_data_len = 1024

        If RegEnumValue(hKey, 0, _
            value_name, value_name_len, 0, _
            value_type, value_data(1), value_data_len) _
                <> ERROR_SUCCESS Then Exit Do

        ' Get the program name the slow way.
        value_data_string = ""
        For i = 1 To value_data_len - 1
            value_data_string = value_data_string & _
                Chr$(value_data(i))
        Next i
        Debug.Print "Removing " & value_data_string

        ' Remove the value.
        value_name = Left$(value_name, value_name_len)
        RegDeleteValue hKey, value_name
    Loop

    ' Close the key.
    If RegCloseKey(hKey) <> ERROR_SUCCESS Then
        MsgBox "Error closing key."
    End If

    MsgBox "Ok"
End Sub