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Article ID: 100834 - Last Review: October 22, 2013 - Revision: 2.0

This article was previously published under Q100834
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The Visual Basic program in this article shows by example how to find the next available (unused) drive letter in Windows. This could be useful when making network connections to a new drive letter.


Step-by-Step Example

The Freedrive function defined below returns the next drive letter available in Windows, followed by a colon (:).

  1. Start Visual Basic. Form1 is created by default.
  2. Add the following code to the General Declarations section of Form1:
       ' Enter the following Declare statement as one, single line:
       Declare Function GetDriveType Lib "kernel"
          (ByVal nDrive As Integer) As Integer
       Function Freedrive ()
          Dim DriveNum As Integer, FirstFreeDrive As String
          Dim FirstDrive As Integer
          DriveNum = -1
             DriveNum = DriveNum + 1   ' start at drive zero.
             FirstDrive% = GetDriveType(DriveNum)
             ' GetDriveType returns zero if it cannot determine drive
             ' type or returns 1 if the specified drive does not exist.
          Loop Until FirstDrive% = 0
          ' DriveNum of 0 means Drive A, 1=B, 2=C, 3=D, 4=E, 5=F, and so on:
          FirstFreeDrive = Chr$(DriveNum + 65) + ":"
          Freedrive = FirstFreeDrive
       End Function
  3. In the Form_click event, add the following statements:
       Sub Form_Click ()
          Print "The next available (unused) drive letter is: "; Freedrive()
          ' More handy tips: The "App" object below is found in VB 2.0
          ' and 3.0 (but not 1.0).
          Print "The title for the EXE in Windows Task Manager: "; app.Title
          Print "The name of this EXE, or project in VB, is: "; app.EXEName
          Print "The path to this application is: "; app.Path
       End Sub
  4. Run the program, and click the form.

  • Microsoft Visual Basic 2.0 Standard Edition
  • Microsoft Visual Basic 3.0 Professional Edition
  • Microsoft Visual Basic 2.0 Professional Edition
kbnosurvey kbarchive kbcode kbnetwork KB100834
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