I am in my bios now and there are options for the booting. I'll just list them:
CD-ROM boot enable
Floppy Boot enable
Internal Network Adapter Boot Enable
Boot mode PXE
Below that there is the order of the booting which the primary is internal optical drive, then it goes through 3 ESB boot options (CD-Rom, Floppy and SuperDisk), then the notebook hdd, usb hdd and then network controller.
In the top right corner it says 1.34 which I'm guessing is the bios version, but I'm not sure.
It seems as if the laptop doesn't start if the power cable is plugged in but the network cable isn't, but it also doesn't start when the network cable is in it by itself. So it's the combination of the power cable and the network cable that makes it start randomly.
I just turned it off and almost straight away it starts up again. It looks like it's now trying to start off the network unless I tell it manually to start off the hdd.
I also did the removing battery and putting it back in. It didn't change anything.