To start off, my ISP is Qwest w/MSN Premium, but prior to having Qwest DSL, my ISP was MSN Dial-up, so I've always had MSN.
After reinstalling Vista Ultimate and Win7 from hardware changes, upgrades, etc, I was unable to install my MSN Premium Software, whether it was the disc or the downloaded installer.
At the MSN Installation Wizard, I would continuously receive a pop-up (each time I ran the MSN Installer) stating that I was not connected to the internet (which I clearly was) and the Wizard could not continue, "Error 235"
I then started scouring the internet for an answer, could not find one and also noticed I was not alone.
I called MSN support, they told me that MSN Premium 9.5 was not compatible with Vista or Windows 7. The tech's did not know what they were talking about, obviously.
I called Qwest support, they were about as helpful as MSN was.
I even put in a "Bug Report" to Microsoft, still waiting.
Could not figure out why it would not install as I had it installed before and it worked great.
The changes that were made were hardware, motherboard, cpu, memory, graphics and 1 new hard drive adding to the 2 I have, so it can't be hardware related.
Using the same software programs as before, so it's not a conflict issue.
Which left a Registry setting being the most likely cause, so after many hours of backing up the registry deleting what I thought would be the cause, then restoring what wasn't, I finally found the (you know what) culprit.
On to the Solution. Installing MSN Premium Software 9.5 Successfully
Click Start/Run, type in "regedit" without quotes to open the Registry Editor
Expand: HKey_Local_Machine/Software/Microsoft/Windows(Not WindowsNT)/Current Version/Internet Settings/5.0/User Agent
Inside the User Agent Folder is a folder named "Post Platform" Delete this folder and click Yes to the pop-up. Close the Registry Editor.
Now you can install MSN with no problems.
Remember, this is a Registry change, so do so at your own risk and please back it up.