PXE is normally one of the boot options in the BIOS. You can generally specify a boot order so that if the machine cannot boot from any local device it will then try to PXE boot, or you can set the PXE option as the first boot option - your choice. However, as you can get it to PXE boot then it seems you have this covered. PXE boot is sometimes called Network Boot.
The Universal NDIS driver is, I believe, part of the option choices in the Ghost Boot Wizard when building a DOS boot environment. However, I would strongly recommend using WinPE as your boot environment as this supports all modern hardware whereas DOS does not.
Here are some links that may help:
https://www-secure.symantec.com/connect/articles/do-i-have-correct-driver-winpe
http://www.symantec.com/business/support/index?page=content&id=TECH110134
https://www-secure.symantec.com/connect/articles/readyadventures-winpe
Do you know which network chipset your T-530 is using? Also, since modern hardware uses SATA hard disks and DOS has no SATA support, you either need to ensure that WinPE has the correct SATA and NIC drivers loaded, or if using DOS, that your BIOS is set to compatibility mode in the hard disk settings. However, I would point out that compatibility mode settings are becoming less common as newer hardware appears and DOS support is withdrawn.