installation issues

[Gireesh]

>Are you suggesting that I should just yum update this F10 installation
>instead of trying to use the USB key disc?

# yum --enablerepo=rawhide update syslinux

will update only the syslinux package and it's dependencies if any.
Your F10 will not be
affected.

> If I press the <Enter> key, I am given a box that says 'Password'

>From your regular F10 install, try this as root with the USB plugged in.
cryptsetup isLuks /dev/sdb1


-- 
Gireesh