我刚装的编译系统，运行时出现下面的东西
Compiling...
b.cpp
d:\program files\c++\microsoft visual studio\vc98\include\iostream.h(52) :
fatal error C1083: Cannot open include file: 'ios.h': No such file or directory
Error executing cl.exe.

请问怎么才能找到这些文件？
谢谢!