You may still need to clarify something, is it a PC or a Sun system?

If it is a Sun system, it inherently supports booting from the network.

If it is a PC, the only way I know that you can confirm if it can PXE boot is to reboot and look at the BIOS settings. Windows and Linux have some tools that interface with the BIOS so you can look at some settings, but I don't recall Solaris x86 having any of these (but it may).

If it is a PC, you may also be able to look at the docs online from the vender that built it to determine if you can PXE boot it.