I use the following code to add the owc10 reference to my project. It
always leads errors on some computers. Your help is highly
appreciated

Dim ref As Object, HasOWC10 As Boolean
For Each ref In ThisWorkbook.VBProject.References
If ref.Name = "OWC10" Then
HasOWC10 = True
End If
Next
If HasOWC10 = False Then ThisWorkbook.VBProject.References.AddFromFile
("C:\Program Files\Common Files\Microsoft Shared\Web Components
\10\OWC10.DLL")

For the computers with such error, I also can not add the reference
mannually IN VBA environment by clicking:

Tools - References - Browse (C:\Program Files\Common Files\Microsoft
Shared\Web Components\10\OWC10.DLL) - OK

gzhu