You could build a PXE Boot server. You can do this using several operating systems, including Debian.
PC2 is configured as a PXE Boot server, potentially using resources from the ISO image. PC1 is then configured in the BIOS to boot from those resources.
There's a lot of stuff required on PC2 to support this, and PC1 needs to support network booting from the BIOS as well.
There's a long write-up on the Debian Wiki, I'll try to summarise it (but the process is quite complex).
- PC2 is your Server.
- You need to install a DHCP service on your server, and configure it to allow booting.
- You need to install a TFTP service on your server.
- You need to get a network boot image, and configure it as a resource within the TFTP service. You can do this using apt on PC2 (the package is known as debian-installer-$VERSION-netboot-$ARCH where $VERSION in your case is 8 and $ARCH needs to match your target machines architecture).
- On your client (PC1) you need to configure the network boot to point at PC2, reboot PC1 and if you've got everything configured correctly it should boot.
Read the Wiki I linked, it has more detail.