Here is a guide to checking iso (after download)
http://www.linuxiso.org/viewdoc.php/verifyiso.html
<<Once the md5sum program has run, and it will take a few minutes to run on a 640 megabyte file, a 32 digit md5sum will be generated. This sum should be exactly the same as the listed md5 sum for the specific iso you downloaded>>
Looking how to enter your bios, see
POLL how do you get into your bios
http://www.linuxquestions.org/questi...ight=poll+bios
oliver37027 welcome to LQ
I do not know Debian, sorry I cannot help.
My only suggestion is you unplug your modem cable
when installing. See if it makes any difference
(it should not find the dhcp server, and would not try
whatever it is trying). But it is a wild guess