Identify the file type first; “.ai” usually means Adobe Illustrator file
Install Adobe Illustrator to open and edit the file
Double-click the file if Adobe Illustrator is already installed
Right-click the file and choose Open With
Select Adobe Illustrator from the list of apps
If you do not have Illustrator, use a compatible viewer or editor such as Affinity Designer, CorelDRAW, Inkscape, or Adobe Acrobat if the file was saved as PDF-compatible
Open the file in a web-based file viewer if you only need to view it
Convert the file to PDF, SVG, or EPS if you need to open it in another program
Make sure the file is not corrupted if it will not open
Update your software if the file version is newer than your app supports