andrewc wrote: Another thought that occurs - could it be Bitdefender AV blocking something?

I'm not familiar with BitDefender - but reading through its specs., it seems to have a finger in every pie. I think it makes a good candidate for causing your problems...
...it's even possible it misbehaves on Windows 7 (just like SmartVPN) ...

hornbyp

Sorry - been a busy week on other things - here are the results of the testing of your various suggestions, so far to no avail I'm afraid :-

1. I checked all the settings on the (remote) 2860 and changed/set the following instead of the defaults

PPTP General Setup
Maximum MPPE (128 bit)

Remote Dial-in User
L2TP with IPSec Policy - Must

Multicast via VPN - Pass

However I had to leave PPTP Enabled in Remote Access Control Setup in case that is what the (working) Win 10 is using (it doesn't say)

2. On my VPN Connection
On Options Tab Unchecked "Include Windows Logon Domain" (I don't use a domain in my home network anyway)
On Security Tab forced it to L2TP/IPSec, then Advanced and set the pre-shared key
On Networking Tab checked File and Printer Sharing

Up until I forced it to use L2TP I was getting error 800 (the remote connections was not made because the attempted VPN tunnels failed).
Using L2TP I now get error 789: the L2TP connection attempt failed because the security layer encountered a processing error during initial negotiations with the remote computer.

Using rasdial from the command prompt I get exactly the same error.

Oh, and I tried disabling all components of Bitdefender and it made no difference at all.

I have still to try copying the .pbk file from the working Win 10 machine.

I'm wondering if some fundamental Windows component is not working here? Even though it was a clean build I had to run a lot of updates and some of them failed and had to be re-run. Yesterday I discovered Sound was not working and had to uninstall/reinstall the IDT Audio device to fix that. Just a thought...

hornbyp

Eureka!

I tried as a last resort your suggestion of copying the rasphone.pbk from the working Win7 machine and Lo! It works!

I suppose it might be worth comparing the 2 files to see what is wrong with the broken one? Not sure how best to understand that... Can I send it to you confidentially in some way?

I have run a compare operation using Textpad and it picks up quite a number of differences between the files but I'm afraid I don't understand the significance of these individual differences.

andrewc wrote: On Options Tab Unchecked "Include Windows Logon Domain" (I don't use a domain in my home network anyway)

I think it might prefix the Username with "Machinename\" in this case...

then he wrote: I suppose it might be worth comparing the 2 files to see what is wrong with the broken one? Not sure how best to understand that... Can I send it to you confidentially in some way?

Intriguing - I really wasn't expecting that...I only suggested it to positively exclude it from enquiries!

There's a slight problem with sending it to me...in that if/when I figure out what the difference is, it'll connect me to your 2860

I think you can use Rasphone to find the difference(s) ...

Rasphone takes quite a few command line options (see: Rasphone -h), but just using the "-f" option takes you into its normal GUI, but using the .pbk file specified by "-f".

You could fire up two instances: i.e. Rasphone -f file1.pbk and Rasphone -f file2.pbk and from the "Properties" option, drill-down through each tab, until you spot it. (The "Connect..." option can be used to absolutely prove, that you've got one working Phonebook and one non-working one).

hornbyp

OK - I'll have a look at it as you suggest.

I'll probably have to fiddle with it anyway since it will be using PPTP and I would really prefer something a little more secure. But I'll back up the file anyway before I start so that I can always get back to a working VPN.

Meanwhile many thanks for your efforts in helping me get to a solution. It is much appreciated.