Step by step instructions on htaccess modification after moving to root directory?

[aliaspt]

Can anyone please point me in a right direction - I just moved the store to the root directory and the product pages show 404 error. What do I need to do with the htaccess file to make it work? I gave it writing permissions but the file has only two lines about php5.
Thank you!
EDITING TO ADD:
This was NOT solved. I never was able to move the subfolder to root directory properly. So, I moved the folder back where it was and added htaccess code provided here http://www.prestashop.com/forums/viewthread/18393/help_installation___upgrade/move_prestashop_from_subfolder_to_root/

[shokinro]

Try to do this
1. At back office - Preferences, set "Friendly URL" to "No" and click "save" button.
2. Make sure you have changed the __PS_BASE_URI__ setting at config/setting.inc.php to root.
define('__PS_BASE_URI__', '/');
3. Go back to back office - Preferences, set "Friendly URL" to "Yes" and click "save" button.
4. Click "generate a .htaccess file" hyperlink which is under Friendly URL section.
Make sure you have set correct write permission on .htaccess file and file.

[aliaspt]

Didn't work.
Do I need to change permissions of other files after moving them to the root directory? They appear to be different from the subfolder permissions.

[shokinro]

I think if you moved the whole folder, all permission setting should be kept as before.

1. try to empty the .htaccess file, then redo the generating, to see if the file is updated, if so, it means not permission problem.

2. set the display_errors to "on" at /config/config.inc.php, and try to re-generate the file again, see if there is any errors.

@ini_set('display_errors', 'off');

[aliaspt]

The htaccess file remained empty. Permissions are set to 666. Where can I see errors? Thank you!

[aliaspt]

So, what worked for me was copying/pasting the old htaccess file and removing the subfolder (/shop/) manually, saving and uploading it back to the server. Now it opens links properly. Do I need to change 'display errors' back to off?
Thank you!

[rocky]

Yes, you should change 'display_errors' to 'off' when you are not using it, so that can see error messages on your site and find out your username.

[aliaspt]

Thanks, rocky, I just changed that back.
I wonder if I should change the title of this topic to "solved". It's not quite solved yet, my website is a mess. But I've been discussing this in another topic.