There isn't a simple answer to the question. There are many factors that go into it: hardware configuration, OS, database, file vaults location, virtualization, extended components (index search, CAD workers, AD integration, etc.), purpose of the Windchill instance, etc.
There are many possible solutions but probably the simplest is to create a VM snapshot for a short term restore point or clone the entire VM for long-term backup. If it isn't a virtual environment, it should be. For portable development environments, VMWare Workstation is under $300 and worth every penny.
