By Windows Mobile
, you mean to say Windows Phone 7 or 8 right? The website of the Windows Phone dev center provides a lot of information on this. What you need:
You can choose between the SDK 7.1 or 8.0, note that you need the 8.0 SDK to develop for Windows Phone 8. Using the 8.0 SDK you can also develop for Windows Phone 7.5.
- Visual Studio:
If you already have Visual Studio 2012 Professional or higher, the SDK templates and tools are integrated into your existing installation of Visual Studio.
- Windows:
Please not that the SDK 8.0 requires Windows 8 Pro 64-bit or higher, thus it's not possible to develop apps for WP8 on Windows 7, as stated here:
Windows Phone SDK 8.0 requires 64-bit Windows 8 Pro or higher. You can't develop Windows Phone 8 apps on Windows 7, on Windows Server 2008, or on Windows Server 2012. The Windows Phone 8 Emulator has special hardware, software, and configuration requirements. For more info, see System requirements for Windows Phone Emulator.
However, you can develop WP7.5 apps on your machine, using the 7.11 SDK.