After you have downloaded the Symantec AntiVirus 9.0 executable above, run the Symantec AntiVirus Install by double-clicking on the SAV9MR4.exe stored on your desktop.
The following will appear. Click Next on the Welcome screen to begin installing the software.
Choose 'I accept the terms in the license agreement,' then click Next.
Click on Complete and then Next.
Click on Install to begin the program installation.
Reboot your computer to finish the installation. At this prompt, simply click OK.
After your reboot, you will be prompted with a screen asking if you would like to update your virus definitions. At the following screen, click Next.
Click on Finish.
This completes your installation of Symantec AntiVirus Version 9.0 for Windows 98 or Windows 98SE.