Antivirus software is essential for protecting PCs from threats, with Windows 11 including Microsoft Defender. Bitdefender offers a range of plans, including family plans for up to 25 devices, while Avast provides a free antivirus option and cheaper Premium Security. Bitdefender's basic antivirus starts at £17.99 for one device, with Premium Security at £59.99, Total Security at £49.99, and Ultimate Security at £69.98. Avast Premium Security is priced at £39.99 for one device. Bitdefender includes unlimited VPN with Premium Security, while Avast requires an upgrade for VPN access. Both offer scam protection, but Bitdefender is noted for its comprehensive features and user-friendly interface. Bitdefender provides 24/7 support, while Avast offers live chat and toll-free support but has a less appealing support layout. Overall, Bitdefender is preferred for its features, ease of use, and support options.