If an anti-malware software is not installed and you don't have access to the internet how can you install it?

If you don't have anti-malware software installed and lack internet access, you can use a portable version of the software stored on a USB drive. You can download the portable anti-malware program from another computer with internet access and transfer it to the offline device via the USB. Make sure to scan the USB drive for malware before transferring it to ensure it is safe. Once on the offline device, run the portable software to perform the necessary scans and removals.