Hello, Does your test app access the file system or anything else like that? Running an app from a network share is a security risk. So .NET sandboxes the app and doesn't let it do certain things. If you try copying the application to the harddrive, does it still cause the security exception? To fix the problem of sandboxing you will need to grant the application permissions to run from the network. Hope this helps, Nathan --------------------------- Hmmm... what's a signature?