Of course for this, you need to first download entire Wikipedia database dumps that are available as .xml, .bz2 file formats then by using some amazing tools you can open this file on your computer for offline reading.
The very first tool is WikiTaxi which lets you – read, search, and browse Wikipedia offline. No Internet connection is needed. All pages are stored in a WikiTaxi database. Because Wikipedia is constantly growing, WikiTaxi uses compression to make sure that the database stays as small as possible. WikiTaxi is embedded with an importer that will uncompress the Wikipedia database files (.bz2) and then convert them into a .taxi file format and this .taxi file can be opened with WikiTaxi. You have to download just one file, the so-called XML dump from the many Wikipedia backups available at WikiTaxi’s website.
To go to WikiTaxi’s website :
The second alternative tool is Kiwix which is easier than WikiTaxi. After installing Kiwix on your computer, download one of the Wikipedia editions which are available at Kiwix website. In this site articles are packaged as .zim file that’ll open directly inside Kiwix without requiring any conversion.
To visit and download Kiwix :