Microsoft Security Essentials
Install antivirus updates offline manually
Description
When your PC lacks internet access, you can manually install the latest virus and spyware definitions for Microsoft Security Essentials. This ensures your protection stays current even without an automatic connection. Simply download the update file from another internet-connected device, transfer it via USB, and run the installer. This process keeps your computer secure against new threats until regular online updates can resume.
Screenshots

Click to view full size
