Windows XP machines are frequently used in "air-gapped" environments or on slow networks where a standard online installer might fail. An offline installer contains all the necessary files in one package, allowing you to install the software without an active internet connection on the target machine.
Windows XP Service Pack 3 (SP3) is highly recommended for stability Windows XP machines are frequently used in "air-gapped"
Use a modern computer to download the offline installer (usually named avast_free_antivirus_setup_offline.exe ). Version 18
Version 18.8 is optimized for older hardware, requiring as little as 256 MB RAM and 1.5 GB disk space . Discontinued Avast support for Windows XP and Vista - FAQs
While Avast has officially discontinued support for Windows XP, you can still download the final compatible version: . Last Supported Version: 18.8.2356
Specifically designed for 32-bit (x86) systems
Complete the setup and restart your PC to activate the shields. Discontinued Avast support for Windows XP and Vista - FAQs