I think you want to download .NET Framework for your mobile phone. If you are using old windows mobile version, from HTC or from any other mobile hardware manufacturers, than it is possible to get the error of .NET Compact Framework, whenever you will try to run or install any new windows applications. The error of .NET Framework, may appear in many different form like “ unknown error 000000 or .NET Framework is not installed into your storage card, or .NET Framework is required to run this application etc.” These all means that you don't have .NET Framework installed into your Windows Mobile Phone, so you need to install .NET Framework into your mobile phone to run the latest Windows Mobile applications. The .net framework error shows into your mobile phone only when if your have old windows OS into your mobile phone i.e. Windows Mobile 5.0 or Windows Mobile 6 etc. The Microsoft .NET Compact Framework 3.5 is redistributable version includes everything you need to test .NET Compact Framework 1.0, 2.0 and 3.5 applications. You can download this .net compact framework for free. The file name is NETCFSetupv35.msi and the download size is 33.3 MB. The Microsoft .NET Compact Framework 3.5 Redistributable contains the common language runtime and class libraries built for the .NET Compact Framework. In addition to version 3.5 support, it also supports applications developed for version 1.0 and 2.0. The .NET Compact Framework 3.5 provides new features such as Windows Communication Foundation, LINQ, Sound Player, new runtime tool support, and many other features.
How To Install .NET Framework Into Your Windows Mobile Phone? To install .NET Framework into your windows mobile, you need to synchronise your mobile with your computer using Active Sync. Their are also another way to install it into your mobile and I think you may be knowing it. This package uses ActiveSync 4.0 to update the device. Before running NETCFSetupv35.msi, connect your device to your PC. If your device is not connected, ActiveSync will store the CAB file and will not install the package until you connect. If you are not using ActiveSync, run the CAB files on the device that correspond to the device–specific CAB files found in the install folder.
System Requirements for installing .NET FrameWork into your old windows mobile. Supported Operating Systems: Windows 2000 Service Pack 4; Windows CE .NET; Windows Mobile 2003 SE software for Pocket PC; Windows Mobile 5.0; Windows Mobile 6; Windows Vista; Windows XP.
Supported Device Operating Systems: Windows Mobile Software for Pocket PC 2003, Windows Mobile 5.0 for PocketPC and Smartphone, Windows CE .NET 5.0 and higher. Download free and redistributable version of Microsoft .NET Compact Framework 3.5, read more about .NET Compact Framework and Download. Important: This download utilities Microsoft® Windows® Installer technology. Windows 98 and Windows ME users should install the Microsoft® Windows® Installer 2.0 before proceeding with this download.