> 2. Error triger: (1). uploading large files (an iso file, larger than 1GB). > The system will freeze randomly during the transfer period; (2) If > fortunately, I can finish up the transfer, I mount the iso file and them > excute a install script, the system freezes. Both these two trigers will let > a Putty window give error messages like: The exact message matters, the one written to the log or displayed in console mode if you are not running X. Also relevant is the hardware list (lspci -vxxx) amd dmesg. Really this is best put into bugzilla.redhat.com If the box has never been reliable also check it seems physically happy - fans are ok etc, and that memtest86 for a few hours finds no faults