[SOLVED] error hosting and domain migration

Hi, I have problems because I want to migrate from a server and domain (called A.com) to another server (called B.com).

I install a fresh opencart in B.com
I change config.php to new server and domain data
I import from phpmyadmin the A.com database

And the problem is that categories of the store go to A.com/category
the product links go to A.com/product-x-x.html

How I can solve this problem?
thank you

Solved:
I need to edit config.php
I need to edit admin/config.php
I need to edit .htaccess for mod rewrite

and problem solved,
thank you

Hi mate I have the same problem my links keep going back to my old site. I see you have solved this, can you tell me what I do with this htaccess file? I checked the configs and I guess they are ok as they only have info on the new domain.
Can you please help?