如果接着下去的提示按Test 的话 会出现
Unable to read the disc checksum from the primary volume descriptor. This probably means the disc was created without adding the checksum.
这样的错误提示
如果按continue 会出现
The Fedora disc was not found in any of your drives. Please insert the Fedora disc and press OK to retry.
这样的错误提示
然后就装不了
checksum（md5检测）：
如果光盘没问题，安装时选择 skip跳过md5检测。
The Fedora disc was not found in any of your drives：
新建好一个虚拟机之后，在提示安装操作系统的时候选择最后一项：
i will install the operating system later，建好虚拟机后再装操作系统
等虚拟机运行好之后再安装。或按F2==>输入检测命令
