为什么我的优盘启动pe后就无法启动了呢？

fuchit

按照长枫三剑客在优盘装好pe后，然后优盘启动进入pe。重启后就直接进入dos界面了。
现实如下：

Sorry！Currently supported dos version are :MS-DOS 3.30 or later;FreeDOS kernel build 2032 and laterl
Programs such as TSRs and device drivers may also change the BIOS interrupt vector table.Make sure those programs are not running,the try again.

我试了好多次了都不行！启动到pe后我没有做任何事，请问到底是什么原因？？谢谢！