Re the mysql err file, that was the first thing I looked for and it wasn't much help as the error occurs very early in the process of mysql starting so it's unable to write to the file and so no details were available there.
BUT! I have managed to solve the problem.
When MySQL was installed (as part of the EasyPHP install) for some reason (perhaps due to it being Win2003) the my.ini file which is in the Windows directory of my XP desktop PC did not exist on the Win2003 server EasyPHP install.
I'm guessing that despite the fact that I was logged in as a domain admin, there is something in Windows 2003 that stops installations from creating files in the root of the c:\windows directory. I'm not a Win2003 server guru so I can't confirm this.
The solution was very simple. Copy my.ini from my XP box to the Win2003 server and modify with a text editor to put in the correct paths.
Regards - Art