Looking up Info-ZIP shows a user-group that have created 'free, portable, high-quality versions of the Zip and UnZip compressor-archiver utilities that are compatible with the DOS-based PKZIP'.
Apparently their versions have been used in quite a number of places.
Some of the more interesting ones (well, historically speaking)
include the use of UnZip code in the unzip.dll distributed with IBM's
OS/2 Warp BonusPak and WebExplorer, as part of the reinstallation code
for the IBM Aptivas preloaded with OS/2 Warp, and as part of IBM's
Infoprint product. Sun used Info-ZIP's self-extractor to distribute
the NT version of their HotJava browser, Novell uses UnZip for NetWare
6 installation, and SAP includes it in Business One. Various Windows
products such as WinZip and the DynaZIP DLLs incorporate Info-ZIP
code, too. And let us not forget Pretty Good Privacy (PGP), an
excellent encryption program that uses Info-ZIP code as a first step
in encrypting files. Info-ZIP's primary compression engine has also
been spun off into the free zlib compression library, used in
Netscape/Mozilla/Firefox, the Linux kernel, Windows, Java, virtually
all PNG-supporting software, and countless other products.
Maybe something in that list points to software you may have installed that included the zip.exe in your windows folder.
zipfldr.dllis in System32. Please read carefully the question. – Steven Penny Jan 31 at 6:55