Do you have an old haswell(original sku)? If you do, you install that chip, update the bios, then install your 4790k. Otherwise, the bios had better be able to handle devil's canyon chips.
This webpage will tell you what bios you need for the newer haswell chips
http://us.msi.com/support/mb/Z87-G45-GAMING.html#down-bios
Final option is use your other computer, set up a usb flash drive to install the newest bios to your new board.
Could also ask your computer nerd buddy, who has an original haswell, to borrow his chip.