It looks like your hard disk has a problem.
PXE usually means you have Network set to boot first.
Try this first:
Go into your BIOS (Check your computer's manufacturer for exact way)
1. Find the "Boot Order" Menu.
2. Make sure the drive on which Windows is installed is enabled on the list (preferably set to first).
3. If you don't know anything, reset your BIOS to its default settings.
If that doesn't solve the problem, try reinstalling Windows 10 (will wipe all data on C partition):
You will need:
1. An empty USB flash drive
2. A working computer with Internet connection
3. Windows 10 Media Creation Tool (located at Windows 10)
1. Download and run the Media Creation Tool, and use it to turn your USB flash drive into a bootable drive from which you can install Windows 10.
2. Insert the flash drive into your computer, and boot into it.
3. Go through the installation process until you are at the Hard Disk page, but do NOT install yet
4. Select the main partition, and click Install.
If you do NOT see a hard drive connected, try:
1. Make sure the hard disk is properly connected (this requires opening your computer)
2. Remove the hard disk and re-insert it.
If your computer's BIOS cannot detect the hard disk, I'm afraid you have a failed hard disk. Try replacing it and installing Windows 10 again.
Thanks for the advice.
I'll give that a go when I get home from work this evening.
FYI, that's not DOS running, it is still the BIOS/POST trying to start an operating system. It isn't finding one, either due to a problem with the drive itself or the bootloader on it. So, the BIOS moving on to the next device in the list, which is the PXE Boot function for your network card.
You don't have to wipe out your existing Windows installation to attempt to fix it. Many people have had great success using Macrium Reflect Free to fix their existing non-booting Windows.
Create a flash drive containing Kyhi's recovery tools:
Windows 10 Recovery Tools - Bootable Rescue Disk - Windows 10 Forums
Boot the computer from that. Run Macrium Reflect contained on it. Under the restore menu is a utility to fix Windows boot problems. Run that.
Thanks for all the advice guys. It's much appreciated!