Max Download Size

I have a directory in IIS 5.1 (Windows XP) that contains 2 files. One being
about 50 MB and the other 3+ GB. I have tuned on directory browsing and tried
to download each file from another computer on the same network. I can
download the smaller file just fine, but the larger will not even try. If do
a Save Target As, I get: "Internet Explorer was not able to open this
Internet site..." in a dialog box. If I click the link, I get an HTTP 500
error. Both files are in the same directory with the same permissions. Is
there a maximum file size built into IIS? If so, can I adjust this?

Any thoughts would be appreciated. Thanks in advance.