Instructions
Open the Start menu and click "Computer." Navigate to the folder in which you've saved the components of your "Minecraft" texture pack.
Press and hold the "Ctrl" key and then click each of the files and folders you want to include in the texture pack. Include all of the folders containing the texture's graphics files, as well as the "pack.txt" description file.
Right-click on one of the selected texture folders. Hover the mouse cursor over "Send To" and select "Compressed (Zipped) Folder" from the menu that appears. Windows will compress the texture pack's files into a zip file.
Type a name for the "Minecraft" texture pack and press "Enter" to save it.