Hello, I have a strange problem. We have develop an application that´s use MODI11 (Feature of Office 2003). Now we have in our office most of PC´s with Office 2003 and the latest Updates (WSUS). Some PC´s are newer and they have Office 2007. We want to create a package to install only MODI in following cases: 1. If User have no office installed than install only MODI on this PC 2. If User have Office 2003, than upgrade the installation with the new feature 3. If User have Office 2007, than install MODI11 side-by-side to to Office 12 installation Point 1: works - we have create a MST an run the MSI with the MST Point 3: works - like Point 1 Our big problem is Point 2: When I install MODI with the MST than MODI works. But when the User open an office application then MSI ask for the PROOF11.msi. I select the MSI on the Application server. That don´t work. Is not upgraded with WSUS Updates (maybe?). So I must remove (With Windows Installer Cleanup) and reinstall office again. Can someone help me? How can I create a working MODI-Package? Thanky you very much Michael