On the computer for administrating the ArcMap-document and the project configuration the following software has to be installed:
⇨ArcMap 10 SP2 with .NET Support (SP 4 recommended; with WebOffice 10R3 SP1 also ArcGIS 10 SP5 is released)
⇨ArcCatalog 10SP2 (SP4 recommended)
ArcGIS Desktop has to be installed with enabled .Net-Support.

.NET Support Installation option in ArcGIS Setup
If the .NET Support was not installed by default, go to Windows Software and Program managing tool, choose “Modify” software and install it additionally.
Note: Minimum requirement concerning the Operating System of the administrative computer is Windows XP SP2 or Windows 2003 Server R2.

Manage installed Software

Modify ArcGIS Setup for Adding .NET Support