Disabling Realtek network boot

dell 7520 laptop 15r SE 1 day old, this must be the most pernickety one Ive had yet or maybe I'm getting old..

Ok, ditched the windows 8 with 3 mins of opening and installed w7 ult after fiddling and faffing with UEF1/legacy etc to get it to boot off the CD

ok now I have a 15sec delay as the realtek nic hunts for a network boot.. So you go into bios I cant find where to turn it off

I find the network boot order    1 network 2 hdd 3 cd but HOW to you reorder it??

Help please and pointers to a good article about UEF1

regards

Peter