Your browser identified itself as a version of IE that was often shipped with default settings that were less than secure. Your internet experience could be made more secure by opening Internet Options in your browser, going to the Advanced tab and looking under the security settings for "Use TLS 1.1" and "Use TLS 1.2". Ensure these are turned on (checked). Doing so will enable your browser to support a higher quality of encryption on this and other websites. You will still be able to browse this site without turning on support for TLS 1.1 and 1.2, but we will have to use a lower level of encryption to accomodate you. See this question on Stack Exchange's Superuser forum from 2011 for more details keeping in mind the comments about TLS 1.2 non-support were made many years ago, and things have changed since then.

If the support for better cryptography has been turned on for your browser, thank you, and you can safely ignore this advisory.

Browser Security Alert

PKZIP has been providing industry-leading ZIP compression for DOS systems for nearly 25 years. PKWARE is committed to file interoperability—files saved using the original PKZIP products can still be opened by any current PKWARE products.


  • Reduces hard disk, floppy disk, and CD storage consumption
  • Provides script PKZIP, PKUNZIP®, and PKSFX functions: Provides script PKZIP, PKUNZIP®, and PKSFX functions with command-line syntax or with batch files on your older desktop PC
  • Long file name support: Supports Long File Names (LFN) (Windows® 95 only)
  • Storage for up to 16,000 files: Backs up your entire hard disk with PKZIP for DOS, producing a ZIP archive with storage for up to 16,000 files
  • Large ZIP archives Offers large ZIP archives across multiple floppy diskettes without having to format disks ahead of time

Note: PKZIP for DOS cannot operate on 64-bit versions of Windows, and no longer comes with technical support. If you require either of these items you may be interested in our Command Line or Server products.

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Technical Requirements

  • For DOS 2.0 and greater, Windows 3.1x, or Windows 95/98, Windows Me*
  • 4 MB RAM
  • 1.2 MB free disk space
  • Not compatible with 64-bit operating systems
  • Technical Support no longer available
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