Huh, after manually upgrading this blog from wordpress 2.6 to wordpress version 2.8, suddenly my blog become error. Yup, when i clicked the post to show single post, it directly connect to 404 error. How come? Is there something wrong when upgrading. I’ve never upgraded my wordpress before. And I’ve followed the instruction correctly when upgrading my wordpress,  like shown below:

1. Download new wordpress version 2.8.
2. Extract wordpress 2.8.zip.
3. Delete “wp-content” folder of the extraction files.
4. Connect to your server, click public html.
5. Delete all files in public html except wp-config.php and wp-content folder.
6. Upload the new files of wordpress 2.8 without wp-content folder (no.3) to public html.
7. Log-in to your blog (http://yourblogname/wp-admin.
8. Click upgrade wordpress and enjoy your new wordpress.

Yup, that’s it all. But after that 404 happened.

I check all the things from wp-config.php, database mysql, etc. Finally I’ve found the problem that the file .htaccess “was deleted. Thanks God, I’ve backed it up.