Site error

I tried to log onto my site (just to view, not login as administrator) and got the following error a the top of the page. No entries displayed and the sidebar if also messed up.
I am thinking I will have to reinstall, but I don’t want to lose all my entries.
Any help would be most appreciated.
Thanks.

WordPress database error: [Got error 28 from table handler]
SELECT DISTINCT * FROM wp_posts WHERE 1=1 AND post_date_gmt <= ‘2005-10-11 02:48:59’ AND (post_status = “publish”) GROUP BY wp_posts.ID ORDER BY post_date DESC LIMIT 0, 10