Media failure..?

ive got a computer problem here.
when i start my laptop, it gives :

For Realtek Ethernet Controller RTL8139 v2.12
PXE-E61: Media test failure, check cable
PXE-M0F: Exiting PXE ROM.

then it restart itself, display the same thing…and again and again

ive searched the internet for possible solutions and found that i can make a bootdisk. it went well until disk 6 then it said:
cannot find cd-rom drive. setup cannot continue

i hope that any computer experts here or someone that has the solution can help me fix my laptop