Windows 7 language packs are available for computers that are running Windows 7 Ultimate

Microsoft has just released all 32 Windows 7 Language Packs for Windows 7 Ultimate RC1.

Windows 7 language packs are available for computers that are running Windows 7 Ultimate. The Windows 7 language packs can be installed only from the Optional Updates section on the Windows Update site. These language packs are not available on the Microsoft Windows Server Update Services (WSUS) Web site or through the Microsoft Download Center.

To download Windows 7 Ultimate language packs, visit the following Microsoft Web site:  http://update.microsoft.com

When you install a language pack, you can change the interface language of Windows 7 Ultimate to the language that you select.
Language packs also let multiple users who share a computer select distinct display languages. For example, one user can choose to see the dialog boxes, menus and other text in Japanese while another user can choose to see the same content in French.
To change the display language, follow these steps:

1. Click Start, and then type Change display language in the Start Search box.
2. Click Change display language.
3. In the drop-down list that appears, select the language that you want, and then click OK.

To uninstall a language pack, follow these steps:

1. Click Start, and then type Uninstall display language in the Start Search box.
2. Click Install or uninstall display languages.
3. Click Uninstall display languages.
4. Select the language or languages that you want to uninstall, and then click Next.
5. Follow the rest of the steps to uninstall this language or languages.

Source: Microsoft Support