Private Declare Function SearchTreeForFile Lib "imagehlp" (ByVal RootPath As String, ByVal InputPathName As String, ByVal OutputPathBuffer As String) As Long
Private Const MAX_PATH = 260
Private Sub Form_Load()
    'KPD-Team 2000
    'URL: [url]http://www.allapi.net/[/url]
    'E-Mail: [email]
[email protected][/email]
    Dim tempStr As String, Ret As Long
    'create a buffer string
    tempStr = String(MAX_PATH, 0)
    'returns 1 when successfull, 0 when failed
    Ret = SearchTreeForFile("c:\", "myfile.ext", tempStr)
    If Ret <> 0 Then
        MsgBox "Located file at " + Left$(tempStr, InStr(1, tempStr, Chr$(0)) - 1)
    Else
        MsgBox "File not found!"
    End If
End Sub
Ah...vai sul link presente nel codice e scarica API-Guide...ti potrebbe essere molto utile... ;)