To capture System Log from 3945N which uses 3Ware/LSI RAID Controllers, download the utility from here, then follow the steps below.
LSI HBA/MegaRAID/3ware Data Collection Script for Win 2K/XP/2K3/Vista and 2K8. This script will collect system logs and info as well as controller, disk and enclosure info for debugging purposes. All files included in the original lsigetwin_xxx_xxxxxx.zip file MUST be kept in the same subdir as lsigetwin.bat. You MUST be an Administrator/have Admin rights to run this script.