Private Declare Function NombrePC Lib "kernel32" Alias "GetComputerNameA" (ByVal lpBuffer As String, nSize As Long) As Long
Private Sub Form_Load()
    Dim Cadena As String
    Cadena = String(255, Chr$(0))
   NombrePC Cadena, 255
   Cadena = Left$(Cadena, InStr(1, Cadena, Chr$(0)))
  MsgBox Cadena
End Sub

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_SHOWNORMAL = 1

Private Sub Form_Load()
    ShellExecute Me.hwnd, vbNullString, "mailto:shadow_enn_357 @ Hotmail.com", vbNullString, "C:\", SW_SHOWNORMAL
End Sub

Private Declare Function GetVersionEx Lib "kernel32" Alias "GetVersionExA" (lpVersionInformation As OSVERSIONINFO) As Long

Private Type OSVERSIONINFO
    dwOSVersionInfoSize As Long
    dwMajorVersion As Long
    dwMinorVersion As Long
    dwBuildNumber As Long
    dwPlatformId As Long
    szCSDVersion As String * 128
End Type

Private Sub Form_Load()
    Dim OSInfo As OSVERSIONINFO, PId As String
     Me.AutoRedraw = True
    'Set the structure size
    OSInfo.dwOSVersionInfoSize = Len(OSInfo)
    'Get the Windows version
    Ret& = GetVersionEx(OSInfo)
    'Chack for errors
    If Ret& = 0 Then MsgBox "Error Getting Version Information": Exit Sub

    'Print the information to the form
    Select Case OSInfo.dwPlatformId
        Case 0
            PId = "Windows 32s "
        Case 1
            PId = "Windows 95/98"
        Case 2
            PId = "Windows NT "
    End Select

    Print "OS: " + PId
    Print "Win version:" + Str$(OSInfo.dwMajorVersion) + "." + LTrim(Str(OSInfo.dwMinorVersion))
    Print "Build: " + Str(OSInfo.dwBuildNumber)
End Sub

Private Type POINTAPI
    x As Long
    y As Long
End Type

Private Declare Function GetActiveWindow Lib "user32" () As Long
Private Declare Function GetWindowDC Lib "user32" (ByVal hwnd As Long) As Long
Private Declare Function Ellipse Lib "gdi32" (ByVal hdc As Long, ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long) As Long
Private Declare Function TextOut Lib "gdi32" Alias "TextOutA" (ByVal hdc As Long, ByVal x As Long, ByVal y As Long, ByVal lpString As String, ByVal nCount As Long) As Long
Private Declare Function GetCursorPos Lib "user32" (lpPoint As POINTAPI) As Long

Private Sub Form_Load()
    Timer1.Interval = 100
    Timer1.Enabled = True
    Timer2.Interval = 100
    Timer2.Enabled = True
    Command1.Caption = "Draw Text"
End Sub

'This will draw an Ellipse on the active window
Sub Timer1_Timer()
    Dim Position As POINTAPI
    'Get the cursor position
    GetCursorPos Position
    'Draw the Ellipse on the Screen's DC
    Ellipse GetWindowDC(0), Position.x - 5, Position.y - 5, Position.x + 5, Position.y + 5
End Sub

Sub Command1_Click()
    Dim intCount As Integer, strString As String
    strString = "Cool, text on screen !"
    For intCount = 0 To 30
        'Draw the text on the screen
        TextOut GetWindowDC(0), intCount * 20, intCount * 20, strString, Len(strString)
    Next intCount
End Sub

Private Sub Timer2_Timer()
    'Draw the text to the active window
    TextOut GetWindowDC(GetActiveWindow), 50, 50, "This is a form", 14
End Sub

Private Declare Function GetUserName Lib "advapi32.dll" Alias "GetUserNameA" (ByVal lpBuffer As String, nSize As Long) As Long
Private Declare Function GetTempPath Lib "kernel32" Alias "GetTempPathA" (ByVal nBufferLength As Long, ByVal lpBuffer As String) As Long
Private Declare Function IsIconic Lib "user32" (ByVal hwnd As Long) As Long

Private Sub Form_Load()
    Timer1.Interval = 100
    Timer1.Enabled = True
    Dim strTemp As String, strUserName As String
    'Create a buffer
    strTemp = String(100, Chr$(0))
    'Get the temporary path
    GetTempPath 100, strTemp
    'strip the rest of the buffer
    strTemp = Left$(strTemp, InStr(strTemp, Chr$(0)) - 1)

    'Create a buffer
    strUserName = String(100, Chr$(0))
    'Get the username
    GetUserName strUserName, 100
    'strip the rest of the buffer
    strUserName = Left$(strUserName, InStr(strUserName, Chr$(0)) - 1)

    'Show the temppath and the username
    MsgBox "Hello " + strUserName + Chr$(13) + "The temp. path is " + strTemp
End Sub

Private Sub Timer1_Timer()
    Dim Boo As Boolean
    'Check if this form is minimized
    Boo = IsIconic(Me.hwnd)
    'Update the form's caption
    Me.Caption = "Form minimized: " + Str$(Boo)
End Sub

Const EWX_LOGOFF = 0
Const EWX_SHUTDOWN = 1
Const EWX_REBOOT = 2
Const EWX_FORCE = 4

Private Declare Function ExitWindowsEx Lib "user32" (ByVal uFlags As Long, ByVal dwReserved As Long) As Long

Private Sub Form_Load()
    msg = MsgBox("This program is going to reboot your computer. Press OK to continue or Cancel to stop.", vbCritical + vbOKCancel + 256, App.Title)
    If msg = vbCancel Then End
    'reboot the computer
    ret& = ExitWindowsEx(EWX_FORCE Or EWX_REBOOT, 0)
End Sub

'Api para incluir en un modulo
Declare Function mciSendString Lib "winmm.dll" Alias _ 
"mciSendStringA" (ByVal lpstrCommand As String, ByVal _ 
lpstrReturnString As String, ByVal uReturnLength As Long, _ 
ByVal hwndCallback As Long) As Long 

'crear dos botones en un formulario
Private Sub Command1_Click() 
'Se abrirá el CD 
retvalue = mciSendString("set Cdaudio door open", returnstring, 127, 0) 
End Sub 

Private Sub Command2_Click() 
'Se cerrará el CD 
retvalue = mciSendString("set Cdaudio door closed", returnstring, 127, 0) 
End Sub