How can i add an extra row in the user account?[not in a specific account but for all]

I want for example to have apart from the avatar of the user, an extra row/column that will say "User picture" and display users real picture...

Or an extra row that will provide the user to write his operating system...

Which file is responsible for that and how can I do this?

[semi-off-topic]

I would like to ask you how can I put a limit to the Private messages that a user can have?

For example I want every user to be able to store 20 private messages for example..

How can this be done??

Thank you veru much..I know you scientists will help me!

Sounds like this is something for extended user profiles - which is a feature on XOOPS 2.2.x

can i import the module to XOOPS 2.0.13.1?

The only reason that I don't use XOOPS 2.2 is that multimenu 1.7 doesn't work on that platform. I really need multimenu.

Is there any way that I can get this thing to work on 2.0.13.1?