InvalidCastException: Unable to cast COM object of type ‘Microsoft.Office.Interop.Word.ApplicationClass’ to interface type ‘Microsoft.Office.Interop.Word._Application’. This operation failed because the QueryInterface call on the COM component for the interface with IID ‘{00020970-0000-0000-C000-000000000046}’ failed due to the following error: 加載類型庫/DLL 時出錯
最后發現是因為最初裝的是Ghost里面自帶的Office 2007的精簡版，卸載2007有殘余，對Office 2003有干擾。查找00020970-0000-0000-C000-000000000046主鍵，下面的TypeLib項為{00020905-0000-0000-C000-000000000046}。再查找{00020905-0000-0000-C000-000000000046}主鍵，下面兩項8.3, 8.4。8.3是Office 2003， 8.4是Office 2007的。將8.4分支刪除。程序運行正常！
一向以為微軟的商業軟件是兼容性最好的，現在看來微軟的兼容性測試也不過如此啊，Office這種重量級軟件還有版本卸載不干凈的問題。
轉自：http://www.cozyboy.com/archives/79.html