I haven't updated my MacBook Pro in many years. In fact, I'm still on Snow Leopard (MacOS X 10.6.8). This is a version so old that all the steps I read to make a bootable USB drive failed. I wasn't able to use createinstallmedia to make a boot disk because that doesn't work until MacOS X 10.7. Nearly all the steps I read online regarding using "Disk Utility" to make a bootable USB drive failed until did the following steps:
General steps This is the step によって step guide for link to 表示する あなた how to convert video (including HD video, MKV, WMV, AVCHD, AVI, MOV, FLV, MOD, TOD, etc.) to portable device, 林檎, アップル optimized format または HD MKV, WMV, AVI video.