It’s possible to install Windows without a DVD player or a USB stick but you have to do some fiddling… I wanted to install Windows 7 on an old PC that had no internal DVD drive and won’t boot from USB so the idea is to create a new partition on the C drive in which to put the installation files and boot from that. Once complete you can remove the ‘install’ partition and re-size the original partition to use the whole disk, or just leave it.
An alternative is to use a bootable CD then run the Windows setup from there using the a USB DVD drive.
You could also use a CD with GRUB on it, boot from that then from the USB. More on that here: