WP import

Following import into WP 3.9 I cannot login.

Live WordPress 3.9 site will be migrated. I obtained files and WP database “globalrec” export – let’s call the file gr.sql

— phpMyAdmin SQL Dump
— version 3.5.2
— https://www.phpmyadmin.net
—
— Host: internal-db.s130692.gridserver.com
— Generation Time: May 01, 2014 at 07:48 PM
— Server version: 5.1.67-rel14.3
— PHP Version: 5.3.27

Steps:
======
I created a new local (Windows 7 64 bit) WP 3.9 installation with db=”gr” and WP site login gr/gr.
I could login and see the typical fresh WP installation with the Hello post and also created new posts.

Logged out from WP.

From phpAdmin I cannot import gw.sql due to primary key validation thus I have to drop every single table from “gr” database.
This clearly indicates import could not overwrite existing structure of the database.

I can successfuly import into “gr” when no tables exist there using gr.sql – I see rows, post titles etc from sql.

The problem:
I cannot login into WP using my original credentials gr/gr which I used when installing WP

Since I don’t know keys when passwords for the live site were created, nothing from gr.sql helped (admin and resp. password)

Note:
I had also WP 3.8.1 installation and imported and logged in but I could not see imported posts and pages.
(I had certain tab plugins which did not work in 3.9 thus I tried to remain in well functioning 3.8.1.)

What can I do?
I am happy to use either 3.9 or 3.8.1 but what to do with this import failed login for WP 3.9 and/or missing posts and pages in 3.8.1 ?

Thanks very much.