Ubuntu Server 12.04 USB disk installation disc read error

Today, with UltraISO, the Ubuntu server 12.04 is engraved into the USB drive installation system, the mediation prompt error from the CD to read data error. The internet searched the solution, many recommended with Win32diskimager this software to burn. For the first time, there is another solution. Here are some detailed explanations:
1. Copy the Ubuntu-12.04-server-i386.iso to the root of the USB flash drive you just burned.
2. Boot from USB flash drive, press ALT+F2 switch to another console when error occurs, enter the following command:
　　

umount /dev/sdc4    //sdc4是我的U盘设备，不同机器可能不一样，可用"ls /dev |grep sd*"查看一下。mkdir /mnt/usb      -t//将U盘挂载到这个文件夹下-t-oloop ubuntu-12.04-server-i386.//挂载iso文件

ATL+F1, select Yes, re-scan, you can continue to install.
　　

Ubuntu Server 12.04 USB disk installation disc read error