using GZIP

[LUIS CARLOS PAGLIARI]

Dear Sir. 
    I need some help to understand how to use correctly the GZIP 
    software . As I am Trying to expand the files of a C++ compiler that I have 
    just downloaded from CIGNUS site, I hope you could tell me why the software 
    doesn't work when I write GUNZIP -d file at the DOS prompt, but when 
    I write GZIP it works. After combining the source files of CIGWIN32 I must 
    expand the result. Isn't GZIP used both to compress and expand files 
    ? Am I doing something wrong ? 
 
pagliari@uol.com.br