how to know if the Msword has been install in the computer?

[Hack]

Here is some code that will return the office component and its current path. This is also from http://www.vb-world.net/

Private Declare Function RegOpenKeyEx Lib "advapi32.dll" Alias _
   "RegOpenKeyExA" (ByVal hKey As Long, _
   ByVal lpSubKey As String, ByVal ulOptions As Long, _
   ByVal samDesired As Long, phkResult As Long) _
   As Long
 
Private Declare Function RegQueryValueEx Lib "advapi32.dll" _
   Alias "RegQueryValueExA" (ByVal hKey As Long, ByVal _
   lpValueName As String, ByVal lpReserved As Long, _
   lpType As Long, ByVal lpData As String, lpcbData As Long) _
   As Long
                                                                                                  
Private Declare Function RegCloseKey Lib "advapi32.dll" _
   (ByVal hKey As Long) As Long
 
Private Const REG_SZ As Long = 1
Private Const KEY_ALL_ACCESS = &H3F
Private Const HKEY_LOCAL_MACHINE = &H80000002
 
 
'*****************************************************
'These functions return the path to the specified office 
'application or a 0-length string if the application does not 
'exist on the machine.  This is one good way to check whether a 
'specific office application is present before trying to run 
'automation code for that application
'*****************************************************
Public Function GetWordPath() As String
    GetWordPath = GetOfficeAppPath("Word.Application")
    'display path
    MsgBox GetWordPath
End Function
 
Public Function GetExcelPath() As String
    GetExcelPath = GetOfficeAppPath("Excel.Application")
    'display path
    MsgBox GetExcelPath
End Function
 
Public Function GetAccessPath() As String
    GetAccessPath = GetOfficeAppPath("Access.Application")
    'display path
    MsgBox GetAccessPath
End Function
 
Public Function GetOutlookPath() As String
    GetOutlookPath = GetOfficeAppPath("Outlook.Application")
     'display path
    MsgBox GetOutlookPath
End Function
 
Public Function GetPowerPointPath() As String
    GetPowerPointPath =  GetOfficeAppPath("PowerPoint.Application")
    'display path
    MsgBox GetPowerPointPath
End Function
 
Public Function GetFrontPagePath() As String
    GetFrontPagePath = GetOfficeAppPath("FrontPage.Application")
    'display path
    MsgBox GetFrontPagePath
End Function
 
Private Function GetOfficeAppPath(ByVal ProgID As String)  As String
 
Dim lKey As Long
Dim lRet As Long
Dim sClassID As String
Dim sAns As String
Dim lngBuffer As Long
Dim lPos As Long
 
   'GetClassID
   lRet = RegOpenKeyEx(HKEY_LOCAL_MACHINE, _
          "Software\Classes\" & ProgID & "\CLSID", 0&, _
           KEY_ALL_ACCESS, lKey)
   If lRet = 0 Then
 
      lRet = RegQueryValueEx(lKey, "", 0&, REG_SZ, "", lngBuffer)
      sClassID = Space(lngBuffer)
      lRet = RegQueryValueEx(lKey, "", 0&, REG_SZ, sClassID, _
          lngBuffer)
 
      'drop null-terminator
      sClassID = Left(sClassID, lngBuffer - 1) 
      RegCloseKey lKey
   End If
   
    
   'Get AppPath
    lRet = RegOpenKeyEx(HKEY_LOCAL_MACHINE, _
        "Software\Classes\CLSID\" & sClassID & _
        "\LocalServer32", 0&, KEY_ALL_ACCESS, lKey)
 
  If lRet = 0 Then
      lRet = RegQueryValueEx(lKey, "", 0&, REG_SZ, "", lngBuffer)
      sAns = Space(lngBuffer)
      lRet = RegQueryValueEx(lKey, "", 0&, REG_SZ, sAns, _
        lngBuffer)
      sAns = Left(sAns, lngBuffer - 1)
      
      RegCloseKey lKey
   End If    
    
    'Sometimes the registry will return a switch 
       'beginning with "/" e.g., "/automation"
    
    lPos = InStr(sAns, "/")
        If lPos > 0 Then
            sAns = Trim(Left(sAns, lPos - 1))
        End If
    
    GetOfficeAppPath = sAns
    
End Function