为什么别人的vc程序在我的机器上打不开？

打开*.dsp时显示：
  E:\\....\*.dsp
  This makefile was not generated by Developer Studio.

  Continuing will create a new Developer Studio project to wrap this   make file . You will be prompted to save after the new project has been created.  Do you want to continue?选yes ,让我另外保存为______一个新的dsp.为什么？怎么办？我不想另外保存一个，只想打开原来的！