So I migrated from VS2008 to VS2010 with my clickonce application. I use to have the 2008 C++ redist as a prereq for my application. Upon moving to VS2010 that option no longer exists and the 2010 C++ redist will not do. I have successfully been able to re-add the 2008 redist into the Visual Studio 2010 prereqs list.
My question is, if I now make the 2008 C++ redist a prereq again, will that break my clients? My clients already have the 2008 redist installed.
Thanks much
No, it will not break your clients, as long as you are targeting the same framework version you were with VS 2008.
The prereq installer, usually called the bootstrapper, is completely separate from ClickOnce. It "bootstraps" together prereq installs to make the experience nicer for end users. That's it. It doesn't do anything special other than download and kick-off all your prereq installs and then launch your ClickOnce app when it finishes.
Now, if you upgraded your app to the 4.0 Framework and a client without the framework runs your app, you're in for some trouble. This is a different issue than your C++ runtime prereq though.