In general, application developed with early version of .NET should run in a
box with later .NET version installed without problem.
However, if the application you are trying to install was wrapped in a
installation package, it is very likely the installation package was tied to
specific version of .NET. That is, during the installing the setup process
would check that specific .NET vesion's existence; if not the installation
would stop. It by no means that the application itself would not run under
newer .NET version.
So, if you can get the application installed by other method (such as
XCopy), I'd bet it will run OK.
On the other hand, .NET 3.5x is just extension on top of .NET2.0, so, with
Win7, you have full .NET 2.0 plus some extra (.NET3.xx). But you do not have
..NET 1.x, which is unnecessary in general. But different versions of .NET
frameworks can live side by side peacefully (except .NET3.xx as .NET2.0's
extension that makes things quite confusing), I'd bet installing .NET 1.1 on
Win 7 would not harm anything. but I did not do it, so it is your choice on
your own risk. I have a VISTA with .NET 1.1 all the way up to .NET 3.51 due
to my development tools (VS2003 to VS2008).
