请问各位大侠MPLAB C18 v3.00编译出错了是什么原因？

Clean: Deleting intermediary and output files.
Clean: Deleted file "D:\pic\aa.o".
Clean: Done.
Executing: "E:\MCC18\bin\mcc18.exe" -p=18F458 "aa.c" -fo="aa.o" -Ou- -Ot- -Ob- -Op- -Or- -Od- -Opa-
MPLAB C18 v3.00 (demo)
Copyright 1999-2005 Microchip Technology Inc.
Days remaining until demo becomes feature limited:  60
Skipping link step.  The project contains no linker script.
BUILD FAILED: Wed Jul 26 20:45:21 2006