Windows 7 Ultimate comes with multi-language support by default. You do not need to install any third party software from the Internet to get multi-language display and input capability. It even comes with multi-language menu too. The features are there, you just have to enable it. Here is how you can do it:
1. Navigate to your Windows orb at the bottom-left of your screen, select Control Panel
2. On Control Panel Window, select Region and Language
3. You will see a window as shown on the left, as you can see, this option lets you adjust the format and language you want to display on your Windows menu and task bar, now, click on Keyboards and Languages
4. On the window as shown, click on Change Keyboards...
5. On the window as shown, click on Add...
6. On the language list window as shown, navigate down the list and check Chinese (Traditional) - New Phonetic and Chinese (Traditional) - Phonetic and click OK
7. You will see Traditional Chinese as one of your input option on the window as shown, click on Apply and then OK
8. You may now be asked to restart your Windows
9. After your Windows comes back alive, you will see, on the bottom-right of your screen, you can see that you have an option to input Chinese
10. You can now input Chinese
Enjoy!!