.Net Compact Framework 3.5:
http://www.alltouchpro.com/index.php?topic=1097.0Mini-Definition from WikiPedia
"The Microsoft .NET Framework is a software framework that can be installed on computers running Microsoft Windows operating systems. It includes a large library of coded solutions to prevent common programming problems and a virtual machine that manages the execution of programs written specifically for the framework. The .NET Framework is a key Microsoft offering and is intended to be used by most new applications created for the Windows platform.
The framework's Base Class Library provides a large range of features including user interface, data and data access, database connectivity, cryptography, web application development, numeric algorithms, and network communications. The class library is used by programmers, who combine it with their own code to produce applications."
It can be downloaded from here;
http://www.microsoft.com/downloads/details.aspx?FamilyID=E3821449-3C6B-42F1-9FD9-0041345B3385&displaylang=en1. Connect HTCTP to PC (via ActiveSync or WMDC)
2. Press the downloaded file (from PC)
3. Install and follow on screen information
4. Soft Reset
Viola!
(NOTE: This install takes some time.)
Hope this helps.