Microsoft Windows provides a utility that allows you to zip multiple files into a single compressed file format. This is especially helpful if you are emailing files as attachments or if you need to conserve space (zipping files can reduce file size by up to 50%).
Zipping Multiple Files
Use "Windows Explorer" or "My Computer" ("File Explorer" on Windows 10) to locate the files you wish to zip. (It will help if you move all the files you wish to zip to a single location.)
Hold down [Ctrl] on your keyboard > Click on each file you wish to combine into a zipped file.
Right-click and select "Send To" > Choose "Compressed (Zipped) Folder."
Your files will be combined into a single folder with a zipper icon on it. Select the zipped file to the "Upload File" submission button.