Hey Mehul, I am not getting what you are meaning by reliable windows 7? Well, to me all the editions released are best at their own, so i must say that each of them are reliable.
From Wikipedia I have found some informations about windows 7 editions which I am sharing so that you can choose the best edition for you.
Windows 7 Starter
- Contains the fewest features
- It is only available in a 32-bit version
- Does not include the Windows Aero theme.
- The desktop wallpaper and visual styles (Windows 7 Basic) are not user-changeable.
- Microsoft originally intended to restrict users of this edition to running three simultaneous applications
Windows 7 Home Basic
- Some Windows Aero options are excluded along with several new features.
- It includes geographical activation restriction, which requires users to activate Windows within a certain region or country.
Windows 7 Home Premium: This edition contains features aimed at the Windows Media Center, Windows Aero and multi-touch support.
Windows 7 Professional
- This edition is targeted towards enthusiasts and small-business users.
- It includes all the features of Windows 7 Home Premium, and adds the ability to participate in a Windows Server domain.
- Additional features include operating as a Remote Desktop server, location aware printing, Encrypting File System, Presentation Mode, Software Restriction Policies and Windows XP Mode.
Windows 7 Enterprise
- This edition targets the enterprise segment of the market and is sold through volume licensing to companies which have a Software Assurance contract with Microsoft.
- Additional features include support for Multilingual User Interface (MUI) packages, BitLocker Drive Encryption, and UNIX application support.
Windows 7 Ultimate
- Windows 7 Ultimate contains the same features as Windows 7 Enterprise but unlike the Enterprise edition
- It is available to home users on an individual license basis.
- Windows 7 Home Premium and Windows 7 Professional users are able to upgrade to Windows 7 Ultimate for a fee using Windows Anytime Upgrade if they wish to do so.
- Unlike Windows Vista Ultimate, the Windows 7 Ultimate edition does not include the Windows Ultimate Extras feature or any exclusive features as Microsoft had stated.
Well, these are all about windows 7 and after sharing all those information I would say that using windows 7 ultimate will be the wisest decision.