Stale content in Apache 2.0.49

I wrote a program (in C), several years ago, that
implemented the client side of an HTTP connection
(using "connect" and friends) to so I could download
content from a server (that happened to be on the
same machine).

To handle the server side, and the content, of the
connection I installed (and ran as a service) Apache
2.0.49 on my machine (running Windows 2000
professional, SP2).

The "DocmentRoot" of the installation is at
"C:\Program Files\Apache2\htdocs". so my
Apache would respond to a request for path, say,
"a/b/c" with the content of file
"C:\Program Files\Apache2\htdocs\a\b\c"

Now, trouble is that I found the file in question
had incorrect content, so I changed it (using a
special Java program I'd written to reformat the file),
and I've verified (both within "WordPad" and
"Visual C++"s binary editor) that the content of
the file has updated to the new, correct, content,
but when I step through the code I'd written
implementing the HTTP request, I can see that
the server still responds (to a write to the client
socket of "GET a/b/c" with the old, broken, content

So does anyone know why the server is
responding with old, stale, content, and how the
content can be somehow refreshed so it's no
longer stale?

Russell