Installing the new Fortinet VPN client on MS-Windows

After the last round of MS-Windows updates, running Fortinet's VPN client on my work laptop (MS-Windows) resulted a BSOD. So I downloaded the new client from Fortinet - round about 1Mb and it didn't take too long. But then I discovered that the thing I had downloaded was not the client, but a downloader to download the client.

This took rather a long time to do its job (on a 200Mb internet link). Meanwhile I:

• Found a spare Linux host,
• ran an OS update/upgrade
• installed openfortivpn
• configured this for first time round
• discovered the remote end does not use a trusted certificate
• reconfigured vpn
• discovered the remote end is publishing routes which trash the local routing configured
• rebooted the server ( I was connecting over ssh)
• made myself a coffee
• RTFM
• Went for lunch
• Came back and discovered the download had finished
• Installed the new version of the MS-Windows client
• Discovered that 
•   1) it had overwritten the old client
•   2) that it would not connect - turns out to be a *different* VPN client from what I had before
• Started downloading something else from Fortinet (as advised by colleague)
• Worked out how to manually set up the routes on Linux and got a working connection
• Finished the task for which I wanted a VPN connection
• Startup the new client and found it was the same as the one I had installed earlier