Just an archive FYI for problems installing iSphere:

TL;DR version: Using "Install New Software" didn't work. Using "Eclipse
Marketplace" worked.

A little background: Windows 7 Enterprise with 8GB RAM. I have both RDi
9.5 and 9.6 installed. iSphere was already installed on 9.5 a long time
ago.

I started RDi 9.6 via "Run as administrator". The first attempts to install
iSphere on 9.6 were via Help / Install New Software...

After selecting all components, I clicked Next, and promptly got a message
above the progress bar, "Cannot perform operation. Computing alternate
solutions, may take a while: 5/15". After ~30 seconds, the "Install
Remediation Page" appeared, giving 3 choices to continue. The default was
to not install the iSphere Message Subsystem. The second choice would
install the iSphere Message Subsystem, but would uninstall "IBM Software
Delivery Platform_1", which is the Start menu folder from which RDi 9.6 is
started. (Weird?) The third option was to "Show original error and build my
own solution"; I didn't even look at this one. I tried the default option,
got the "Install Details" dialog, clicked Next, got a "Problem Occurred"
dialog that ended with "HttpComponents connection error response code 429."

I remembered reading in this list recently that folks were having problems
installing iSphere, so I found Dave Clark's thread in which Thomas
mentioned Eclipse Marketplace (on the Help menu). I tried that, searched
for iSphere, it found version 3.2.5, I selected all components, clicked
Next, boom, done.

YM, of course, MV.

- Dan