Thanks for your patience, Jerry.  I added -ms to the end of both of the target lines, and now it works!

I would like to have two Pegasus Mails running at the same time, each with a different user - I understand this can be done.  Sorry if I'm being stupid, but the way I pictured it was two pegasus icons on my desktop, each with a different line in the target.  The default seems to be -roam -A.  Could someone help me with exactly what it should be, and if the two icons are possible?  And again, it might be a stupid question, but is the command line referred to in the Help the same as the target line in Properties?  Could anyone who can help me, please assume I'm a complete idiot, and tell me what to do in words of one syllable? 

One word, one syllable=Help menu and Commandline options and see:

-MS (no parameter)
Start multiple sessions of Pegasus Mail. Use this switch if you want a new copy of Pegasus Mail to start up when the program is run, instead of control simply being transferred to any copy that might currently be running on your system. This switch is usually only useful when combined with the -I or -U switch to specify a user. WARNING!!  This switch DOES NOT allow you to run two copies of Pegasus Mail that simultaneously access the same mailbox: all running copies of Pegasus Mail on the system must be accessing different mailboxes. If you ignore this warning and allow two copies of Pegasus Mail to access the same mailbox at the same time, then you will almost certainly end up with loss of data.

Also see -I

Target line and commandline used in command prompt are/may be the same just entered different place. Two desktop icons are the way to do it and how I do it here plus different description on each icon for easy visual reference.  A typical target line/properties of icon might include C:\PMAIL\Programs\winpm-32.exe -roam -A -i admin -id gmail-jerry

for example.

Thanks for your reply, Jerry.  If there are two users set up on Pegasus, do they each already have their own mail boxes?  I've always assumed this was the case, but your warning has made me nervous.  I think that part of my problem is that I've been using Pegasus for so long (over 20 years - wow!) that I'm stuck in old ways, and haven't been checking what is happening on new editions.  I used to have three separate email addresses, but for the past few years that hasn't been necessary.  I have to admit that it's only now that I need to add a user that I've discovered that the 'change user' has gone...

I'm not sure when to run the -MS.  I tried that (taking out the -roam and -A), and nothing seemed to happen - it just went into Pegasus asking for the username.  There weren't any identities, so I just added the switch -i Herbal to one of the icons, and the other was -i Elaine in the target line.  Both worked, going straight into the user, but it won't open two - I have to close one to get into the other.  So I created two new identities, and used those, so that my switches were: "-roam -A -i Elaine -id Elaine Personal", and the other was "-roam -A -i Herbal -id Herbal College".  This time nothing at all happened - the programme flashed up and then disappeared, so apparently I'm doing something wrong. (I'm actually trying to help my sister, so all of this is happening on another computer).

With your warning about the mailboxes I want to get to understand that completely before I mess everything up...

First please do Help menu, About and Info button and copy all that display and post it. That will show us exactly what you have now and where it is located in addition to version number being used.

The distinction between User and Identity is quite definite but also quite handy for the users. With users each has own mailbox files in ..pmail\mail\<username> location on drive. With Identities not so and just one message store but most all other settings may be per identity and each has own section within the pmail.ini file for settings.  There are differences with Tools, Options, as well as Tools, Internet options and settings.

The short summary is that Usernames have all separate and really are only sharing the executable and files while all in ..pmail\mail\ and below are different. The use of the  -ms switch on command line in addition to other switches is entered into command line used or the target of icon  properties. The -ms is in addition to the normal default -roam -a on the line following the winpm-32.exe portion of complete path. When -ms is used that allows second or other instances as different user (the -i<name> to Start instance as that user while others are already running.

The info button display will also show last commadline used to start winpm-32.