Locked login in re-install

I have just had my laptop upgraded from MSWindows XP to Windows 7. This
included putting in a larger hard disc. Virtual Risc PC -Adjust has been
re-installed, with files copied over from the old hard disc.
However there are some problems with Messenger Pro. It is set up with two
users; 'Jenny' and 'BCA'. When we try to log into 'Jenny' Messenger is
asking for a password. I do not ever remember setting a password and have
not used one normally. It is my default login.
This means I cannot read my recent emails, access most of my email
addresses or distribution lists.
Does anyone know how I can into Messenger without the password or reset it?
There are no problems when logging into 'BCA' and all the emails, addresses
or lists attached to that user.
At present I am avoiding using NetFetch until this is sorted.

Jenny Cornwell.
Sadly using her iPhone and Gmail.