If you are transferring your old blog to a new URL or else reinstalling your whole blog because of some updates or broken scripts then its very important to take a complete backup of all your blog posts, user comments and other blog information which was mostly created by you. WordPress offers a very easy 2 step option for making this process user friendly.
Just login to your wordpress admin dashboard panel and go to the Manage > Export option which is one of the top menu option in your admin dashboard. Here you can export all the data ie your posts, pages, comments, custom fields, categories, and tags in a XML file which can be easily imported to another blog or your reinstalled blog. You can also export this information on the basis of author’s. This option is very useful when only some / one author is moving out from the blog and is looking to transfer his individual posts from the current blog.
Once you click on the ‘Download Export File’ you will be given with the XML version of all your important data from the blog and you need to save it to your computer’s any partition.
Next we need to Import this file to the wordpress for which you need to go to Admin Dashboard > Manage > Import , and click on the ‘WordPress’ link because we are going to import a file which has been exported from a wordpress blog. This option is used for ‘Import posts, comments, custom fields, pages, and categories from a WordPress export file.’
Next you will be directed to a page, where you can browse for the exported file which should be a maximum of 2mb and then click on ‘Upload & Import’ for uploading the file and importing the posts. After this you need to assign the data to the default admin account or else to any selected account. All the posts are imported in the same format with the post date and scheduled dates in case. You will get a complete report of the same in the same page where you can review all the progress of your blog posts exporting and importing job.
you can do a mysql backup too… that would be better