| Features | Why would you need it | Windows 7 Home Premium | Windows 7 Professional | Windows 7 Ultimate |
|---|---|---|---|---|
| XP mode | to run ve..ery old programs | N | Y | Y |
| Domain Join | Work from home | N | Y | Y |
| Data Backup and Restore | To back up Data automatically. | Y | Y | Y |
| Complite System Backup and Restore | To back up entire system automatically. | N | Y | Y |
| BitLocker | If you want to hide something. | N | N | Y |
| 35 languages interface simultaniusly on different user accounts | If few users of the same PC want to read Windows menus in different languages | N | N | Y |
Also there are 32 and 64 bit versions. Generally 64's are for modern dual core CPUs and 32s are for old Pentiums 4 and some laptops and portables.
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