Previous Installations

My server has .NET Framework 1, 2, and 3 installed. I am ready to install 3.5.
Should I delete (remove program) 1,2, and 3. An e-mail server (web based) is
using 1.1.4 and not using the 3.0 installed. If I remove 1,2 will it
automatically find and use 3.0 (or 3.5) or will this require a reinstall?

The server can have all versions of the .NET framework installed together. Your
site/virtual directory has a setting for which version of the framework to use.
The setting is in the 'ASP.NET' tab of the site properties dialog.

But are they required, or just the lastest version? Space. space, space eaten up
if unnecessary. In ISS > DOMAIN > web sites > ASP.NET, the drop down
box does not offer any choices other than 1.1.4322. Is something amiss? I need
at least 2.0.50727. In the Virtual Path it has web.config in the location box it
says C:\Windows\Microsoft.NET\Framework\v2.0.50727\config\web.config. 

I am not a .NET person, but applications we are using are requiring v2 or v3 and
I notice 3.5 is available.

1.x apps will run under 1.1, 2.0 apps will run under 2.0 and 3.0 and 3.5 are
extensions to 2.0.  If you don't run apps of the type, you don't need the
framework installed.  Your issue is you need to register the framework with IIS,
run aspnet_regiis.exe -i for the framework you choose.

Jeff