" 2003-07-28 09:01:27.38 spid75 Error: 823, Severity: 24,
2003-07-28 09:01:27.38 spid75 I/O error 1117 (The request could not be performed because of an I/O device error.) detected during read at offset 0x0000002d460000 in file 'e:\program files\Microsoft SQL Server\mssql\data\mydb.MDF' "
There is a nice tutorial written in Squidoo, where someone who is also using SQL server faced this kind of situation. Check out his blog for SQL data recovery and you might be able to know and rectify in much better way and resolve your error 823 in much easier way