.isproj cannot be opened because of its project type (.isproj) is not supported

Question

I've got 2 VS 2008 based solutions I'm opening up and both have projects that are .NET 3.5. But when I open both solutions in VS 2008, both have some .isproj file(s) and I get this stupid error right after I open the solution:

c:....\somefilename.isproj cannot be opened because its project type (.isproj) is not supported by this version of the application.

When I open the .isproj I see that the project version appears to be VS 2008:

9.0.30729

So I do not understand why I'd still be getting this error and I have never even seen or at least had an error with a file of extension .isproj in any of my apps before. I guess it is used for MS Build?

Answer 1

.isproj is for "InstallShield MSBuild Project File" and to use it, you would need to buy proper tools (more info here https://www.flexerasoftware.com/install/products/installshield)