Problem logging in after moving files – it's not my url settings

1. No, it was mostly html
2.Yes, the site includes a shopping cart that uses a database, but I believe it’s a separate SQL server db, not the MySQL
3. The live site is at example.com; wordpress was installed on example.com/blog. I moved the files from ../blog to the root according to the directions (at least I thought I did it accordingly), but never installed wordpress a second time.
4. After copying the files, I did not create a new database. I backed it up once I couldn’t login so I could go in and verify the site url, but no new db was created.
5. n/a since I didn’t create any new database.

Also, the WP site was running great from ../blog. The plan was to get the content all completed and then make it my “index” page, redirecting old files to the new WP pages.I kept it in a “maintenance mode” while I worked on it and tested it live every day. I thought maybe the plugin was an issue, but I was able to get on the admin panel that one time, so I don’t think that’s it.

(Thanks for helping)

By the way, line 17 of my ..blog/index.php file is:

require( dirname( __FILE__ ) . ‘/wp-blog-header.php’ );

As a follow up for people who are curious:
I had to re-install everything in my desired directory and saved most of it through import/export. I think I had three issues – which started to cross-pollinate, so to speak.

1. I originally wanted my wp files in a non-root folder, but my home page in the root folder. I may have confused the “site” and “home” definitions.

2. I had a page called “blog”. But the folder my wp files were in was also called “blog”. So when looking for http://www.mysite/blog it could have meant my wp page OR my ftp folder, causing a problem for the browser looking for that url.

3.I had a screwy plugin. It wasn’t screwy when I started the migration. But in the midst of all this, when I had a glimpse of my dashboard, there was an update available – which I thought might help. That update screwed up websites all over the world.