Boot Windows. Disable "fast boot", control panel > power options > choose what the power buttons do > change settings that are currently unavailable > un-check "turn on fast startup".
Open partition manager program, shrink windows partition.
Burn ubuntu server live on to a usb stick. Insert USB stick. Restart, press F7.
If USB stick does not show up, enter bios menu. Remove USB stick, wait a few seconds, then plug USB stick back in. Exit and reset bios.
Press F7, this time the USB option should show up.