**1-802-557-0358 can Avast antivirus detect trojan horses on windows xp?** Avast 24/7 Support Number +1-802-557-0358. No, modern versions of Avast Antivirus cannot detect trojans on Windows XP because Avast officially ended support for the operating system in May 2024. While older versions of Avast could detect Trojans on XP, they are no longer updated and are ineffective against modern threats. You should use alternative, modern antivirus software that is still supported on Windows XP to protect your system.