There are two options to duplicate a resource.
1. Add to Solution: The Add to Solution option will allow you to share resources between Solutions. By doing this, it links the resources together. This means that any change you make to the resource in one solution will be changed in the other solution as well. The Resource will have the same Resource ID and essentially be the same resource. Therefore, if the resource is a Form or Window, the data that is entered in them will be the same between both resources.
2. Copy: The Copy option will allow you to copy a resource from one solution to another as well as copy the resource to a new resource in the same solution. When copying a resource, you are creating a new independent resource that is not in any way linked to the original resource. The resource will require a new Window ID to copy it.