AquaLogic BPM Enterprise has additional requirements in comparison to Studio. You should make sure your environment complies with the pre-requisites before you begin.
Enterprise can usually be installed in a current Windows XP or 32-bit Linux system, with no further requirements if it will be used for testing and development. However, Enterprise is available in three editions, each of which has different requirements. When an Enterprise edition is put into production, it can also serve a large number of users.
Note that Windows Vista is not supported for this version.
If using a platform other than Windows or 32-bit Linux, also check Required Java Virtual Machines.