guestbook error

This guestbook was working for months. I havent' done anything but am now getting this error:

Query Error
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MySQL Error : Query Error
Error Number: 1016 Can't open file: 'book_data.MYD'. (errno: 145)
Date : Mon, April 26, 2004 16:54:38
IP : 68.250.253.60
Browser : Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; .NET CLR 1.1.4322)
Referer :
PHP Version : 4.3.1
OS : Linux
Server : Apache/1.3.27 (Unix) PHP/4.3.1 FrontPage/5.0.2.2510
Server Name : www.djhectorlopez.com

If I just reinstall the guestbook which files do I need to backup from the server to keep the old guestbook entries?

Any help would be appreciated.