Booting from USB results in Black screen with blinking underscore?

[New8]

Built my first computer recently, and I went to install Windows xp on it (Because windows 8.1 didn't want to work) and my computer doesn't have an optical drive, so USB was my only option. When I plugged it in and went to boot priority in BIOS, it came up with "UEFI: FNK TECH USB CARD READER" and just "FNK TECH USB CARD READER". I didn't know which to choose so I tried both. Each time, it ended in a black screen with a white blinking underscore. What do I do?

 

[TopLuca]

make sure your USB is a bootable drive with the correct installation files.