Compared to Home Premium and Professional, the Ultimate version has more features like BitLocker Drive Encryption and Multilingual User Interface.
The 32-bit version of Windows 7 Ultimate support up to 4 GB RAM while the 64-bit version supports up to 192 GB RAM. Ultimate and Enterprise editions are almost identical in terms of features, only licensing plans and upgrade options are different. Windows 7 Ultimate is the highest in all editions, and was targeted at home PC users.