Setup: VS 2010, Outlook 2003, Windows XP

The Shim Wizard created all the components properly but when I try and
build the Managed Aggregator I get the following error:

.Net Framework v3.5 Service Pack 1 was not found. In order to target
".NetFramework,Version=v2.0", .NetFramework v3.5 Service Pack 1 or
later must be installed.

The computer has VS2010 installed so .Net Framework 4.0 is present.

Question:
1. How do I get the Managed Aggregator to build on this computer... is
there some thing in the shim Generated code that I need to change to
target v4 of the Framework.

Thanks
Sanjay