We still have CF 1.0 projects or project which is used for an autorun app which gets shipped on a memory card on PPC 2003 SE and later because CF 1.0 is installed in ROM from PPC 2003 SE. Doing this enables our application to self-install on cold-boots or power failures.
Luckily it isn't too difficult rolling back your projects (although you should use some kind of source control system to roll back to). If you don't a source control system or just curious how to do it, it is dead easy.
Simply open up the project and change the ToolsVersion attribute to 2.0. Change the TargetFrameworkVersion element to 2.0. You can get rid of the Import element which specifies CF 3.5. IE:
<import condition="'$(TargetFrameworkVersion)' == 'v3.5'"
Ensure a CF 1.0 or CF 2.0 exists. If you have a desktop project you might have a
<requiredtargetframework>3.5</requiredtargetframework>for some of the framework assemblies, if rolling back, these can be deleted.
Rolling back the solution couldn't be easier. At the header of your solution file (.sln) you'll have the following:
Microsoft Visual Studio Solution File, Format Version 10.00
# Visual Studio 2008
Change the above to:
Microsoft Visual Studio Solution File, Format Version 9.00
# Visual Studio 2005