Consult your hosts user knowledge base or FAQ, or contact their support group for instructions on how to properly enable mod_rewrite/permalinks for your hosting plan and server platform. It may be something as simple as WordPress not being able to write to your .htaccess file due to permission or ownership issues, or might be more involved than that. Some reference material: Using Permalinks
Enabling Pretty Permalinks in WordPress
This walkthrough describes how to enable "Pretty Permalinks" for blog posts in the WordPress blog engine that is installed on IIS 7 and above. Typically, without URL rewriting functionality on a Web server, WordPress users must use "Almost Pretty" URLs, for example, http://contoso.com/index.php/yyyy/mm/dd/post-name/. By using the URL Rewrite module, you can use "Pretty Permalinks," for example, http://example.com/year/month/day/post-name/, for WordPress blogs that are hosted on IIS.
How to Fix Not Working Permalinks in WordPress
Thank you Darshan for passing by, and making your contribution. In case anybody else is wondering, you can re-submit your permalinks by navigating to Settings -> Permalinks in your WordPress admin.
Next, choose a different permalink structure from what you currently have. Click the Save changes button. After that, select the original permalink structure you had and hit the Save changes button once more. Thanks once again Darshan for sharing your findings. Cheers!