Microsoft have updated their Windows CE 4 code runtime package, the Microsoft .NET Compact Framework 1.0. The updated release, now at Service Pack 3 (SP3) includes everything you need to run .NET Compact Framework applications, including the Common Language Runtime and the .NET Compact Framework class library.

The update is purely a bug fix release to improve stability and fix bugs reported from developers. The download is free for all users and work with devices running Windows CE 4.1 and 4.2 and the Pocket PC.
You should dock your device to the host before beginning the setup process.

View: Microsoft Download Centre