try adding the class name:

Nome_Maquina = vba.Left$(Maquina, vba.InStr(Maquina, vbNullChar) - 1)

>i have a simple workbook under excel xp (portuguese) (windows 200o professional sp4);
>
>if i try to execute the same workbook under excel 2000 (portuguese) (windows xp home) or under excel 97 (windows 98 se) i receive the error "it's impossible to find project or a library"; i try to solve the problem with help, but doesn't work!
>
>the error came with the follow command (workbook_open)
>
>Nome_Maquina = Left$(Maquina, InStr(Maquina, vbNullChar) - 1)
>
>the error is locate at the function left$!
>
>sergio