Danke schon mal.
Jetzt hat sich was geändert. Es kommt folgende Meldung:

> "make.exe" all

-------- begin --------
avr-gcc (GCC) 3.4.3
Copyright (C) 2004 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.


Linking: main.c.elf
avr-gcc -mmcu=atmega163 -I. -gstabs -DF_CPU=8000000UL -O0 -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums -Wall -Wstrict-prototypes -Wa,-adhlns= -std=gnu99 -MD -MP -MF .dep/main.c.elf.d --output main.c.elf -Wl,-Map=main.c.map,--cref -lm
E:/winavr/bin/../lib/gcc/avr/3.4.3/../../../../avr/lib/avr5/crtm163.o(.init9+0x0): undefined reference to `main'
make.exe: *** [main.c.elf] Error 1

> Process Exit Code: 2