回复：明白了...

多谢您。我想是当初坏的C盘没拿掉，在第二个hard drive 上装的 Widow XP OS. Then he found out that 还是不能正常运行window， 就把原来坏的C盘拿走了。剩下唯一一个硬盘显示为E盘。

I will take your advice and not have any USB readers plugged in when reinstalling the window OS.

Thank you very much for your help.