Microsoft KB Archive/141020

= How to Find Next Available Drive Letter (for Network Connect) =

Article ID: 141020

Article Last Modified on 12/9/2003

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APPLIES TO


 * Microsoft Visual Basic 4.0 Professional Edition
 * Microsoft Visual Basic 4.0 Professional Edition
 * Microsoft Visual Basic 4.0 16-bit Enterprise Edition
 * Microsoft Visual Basic 4.0 32-Bit Enterprise Edition

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This article was previously published under Q141020



SUMMARY
The Visual Basic program in this article shows by example how to find the next available (unused) drive letter in Windows. This is 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.

 Start Visual Basic. Form1 is created by default.  Add the following code to the General Declarations section of Form1: Private Declare Function GetDriveType Lib "kernel32" Alias "GetDriveTypeA" (ByVal nDrive As String) As Long Private Declare Function GetDriveType Lib "kernel" (ByVal nDrive As Integer) As Integer
 * 1) If Win32 Then
 * 1) Else
 * 1) End If

Function Freedrive Dim DriveNum As Integer, FirstFreeDrive As String Dim FirstDrive As Integer DriveNum = -1 Do        DriveNum = DriveNum + 1   ' start at drive zero. #If Win32 Then NextDrive$ = Chr$(DriveNum + 65) + ":\" FirstDrive% = GetDriveType(NextDrive$) #Else FirstDrive% = GetDriveType(DriveNum) #End If        ' GetDriveType returns zero if it cannot determine drive ' type or returns 1 if the specified drive does not exist. #If Win32 Then Loop Until FirstDrive% = 1 #Else Loop Until FirstDrive% = 0 #End If     ' 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   In the Form_click event, add the following statements: Private Sub Form_Click

Cls 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  Run the program, and click the form.

Additional query words: 2.00 3.00 4.00 vb4win vb4all

Keywords: kbnetwork kbcode KB141020

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