I have an application that, as part of its installer (created using WiX), deploys a certificate to the Trusted root CA list in the local machine store. I've had users complain that the install can fail to compelte, and it looks like the certificate install is to blame. When I look into the system though, I've noticed that the root CA cert already exists in the store multiple times. The question is-how can you add the same certificate (with the same serial number) twice to the same certificate store? I've tried importing it, and I've tried various permutations of the installer, and in no case have I been able to create a scenario where the certificate store gets into this state. Has anyone ever seen this behavior before, and if so, is there a way to duplicate it? If I can create a VPC image that replicates the duplicate certificates, then I can work on troubleshooting the original installation issue.Thanks for your help!

This seems an issue regarding installation package. I'd like to inform you that the certificates are stored in different places. (To show it, click View->Options, and select "Physical certificate stores".) Meanwhile, as this forum focuses on Windows Vista specific issues, we are not the best support resource. I suggest you can involve the developer of the application WIX to check the related code or contact their support for further assistance.