[問題] 論壇出現錯誤訊息

[pink]

◇OS:WinXP
◇網路:8M/640
◇主機:AMD 1G +1.2GRAM
◇PHPBB:2.0.6
◇安裝的程式：Apache + php + MySql
◇網址:http://220.135.105.176/phpbb2/index.php
◇問題描述:
今天忽然發覺無法進入論壇,一進去後出現:
===============================
phpBB : Critical Error

Could not obtain lastvisit data from user table

DEBUG MODE

SQL Error : 1016 Can't open file: 'phpbb_users.MYI'. (errno: 145)

SELECT * FROM phpbb_users WHERE user_id = 4

Line : 62
File : C:\Program Files\Apache Group\Apache2\htdocs\phpBB2\includes\sessions.php
===============================
請問各位前輩這情況該如何修復呢?
不知道是不是因為家裡忽然停電導致論譚掛點 >"<