Be sure to have an .htaccess file in the root directory with the following in it:
RewriteEngine On
RewriteBase /
RewriteRule ^index.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
Category: WordPress
Run this query:
UPDATE `wp_users` SET `user_pass`= MD5('yourpassword') WHERE `user_login`='yourusername';
Run this query:
UPDATE `wp_users` SET `user_pass`= MD5('yourpassword') WHERE `user_login`='yourusername';
Manually update, download a fresh copy and replace all files and folders. Backup everything before just in case.
Rod Tech Blog 