Private Declare Function GetSystemDirectory Lib "kernel32" Alias _
"GetSystemDirectoryA" (ByVal lpBuffer As String, _
ByVal nSize As Long) As Long
Private Declare Function GetWindowsDirectory Lib "kernel32" Alias "GetWindowsDirectoryA" (ByVal lpBuffer As String, ByVal nSize As Long) As Long

Private Declare Function ShellExecute Lib "shell32.dll" Alias _
"ShellExecuteA" (ByVal hwnd As Long, ByVal lpOperation _
As String, ByVal lpFile As String, ByVal lpParameters _
As String, ByVal lpDirectory As String, ByVal nShowCmd _
As Long) As Long

Const SW_SHOW = 5

Private Sub Command1_Click()
Dim sFor As String
Dim sTemp As String

sFor = String(260, " ")
GetWindowsDirectory sFor, 260
sTemp = Left$(sFor, InStr(sFor, Chr(0)) - 1) + "\rundll32.exe" _
+ Chr(0)
ShellExecute Me.hwnd, vbNullString, sTemp, _
"Shell32.dll,SHFormatDrive" + Chr(0), "c:\" + Chr(0), _
SW_SHOW
End Sub