求助：allegro pcb editor 出现问题

求助各位大虾，我在用allegro pcb editor 布线时发现布不通了，所以就关掉软件，把原来用的文件夹删掉，然后将备份的文件夹复制过来改成更原来文件夹相同的名字，以为这样就可以重新来过，免得一个个手动去删一些线和过孔，结果打开pcb editor时，电脑提示：file "**.brd" was locked on date "july 2012~~~~" by user administrator on system "~~" would you like to override the lock ?,求大神指点啊。