Login names (also called 'login', 'user name', 'identifier' and 'ID') are issued automatically as described in Registration.
The login name is made up of "a" or "n" followed by the middle seven characters of the Student Number (why?). Thus if the Student Number is 079652243, then the ISS login name would be a7965224.
The login name is made up of "n" followed by the user's initials.
If another user with the same initials already exists at the University (or has existed in the past), numbers are added to the login, e.g. nrs23.
All users have the University Campus Managed Desktop (Windows) service as their main service; initial passwords are set automatically, or by IT Service Desk staff.
To re-set your password, simply press Ctrl-Alt-Del after logging in successfully on an ISS or Managed Desktop PC and choose the Password option. Windows has extremely complicated rules for passwords, and will reject a "weak" password: advice on choosing a password is available if you get stuck.
Unix accounts are entirely separate from Windows accounts. Although users always have the same login name for ISS systems, the passwords can be different if desired.
Resetting a windows password will also reset the Unix password. New Unix accounts are set up to have the Windows password.
Almost all University online services now use the ISS Windows login name and password, thanks to various forms of cooperative working between systems.