Moving URL from site root

I installed WP in my root directory, but now I want to move it to a sub directory. It was originally installed to http://mysite.com/ – but I now want to move it to http://mysite.com/blog (I’m now only going to use it as a blog within my website.

I have altered the wp-config.php by adding two lines to it where “example.com” is the NEW location of my site.

define(‘WP_HOME’,’http://mysite.com/blog’);
define(‘WP_SITEURL’,’http://mysite.com/blog’);

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I also changed option_name=’siteurl’ in wp_options table from http://mysite.com/ to http://mysite.com/blog/ (and back again and tried just with the two included lines to wp-config.php)

I get the same error regardless of which ‘siteurl’ I choose in the wp_options table:

http://mysite.com/blog/wp-login.php = Page not found
http://mysite.com/wp-login.php = can log in, but then redirects to /blog (page not found)

I did also try moving the files to a sub-directory prior to trying this, but if I do that I can’t even get to the log in page.

I have followed instructions in the following articles:
http://codex.ww.wp.xz.cn/Changing_The_Site_URL
http://codex.ww.wp.xz.cn/Moving_WordPress#Moving_WordPress_Within_Your_Site
http://codex.ww.wp.xz.cn/Giving_WordPress_Its_Own_Directory

I know I’m missing something really minor as I can still log in, but form some reason /blog is not showing up as a valid path.