Lenovo still releases drivers for the T420 which is 10 years old! : r/thinkpad
Lenovo ThinkPad T420 4236-63U 14" Laptop i5-2540M - Windows
Amazon.com: Lenovo ThinkPad T420 14" LED Notebook Intel Dual Core i7-2640M 2.80GHz 4 GB DDR3 RAM 128GB SSD DVD-RW WiFi Bluetooth Webcam Windows 7 Professional 64-bit : Electronics
Refurbished: Lenovo ThinkPad T420 14" Notebook with Intel Core i5-2520M 2.50 GHz (3.20 GHz Turbo), 4 GB RAM, 320 GB HDD, DVD-ROM, Windows 7 Professional COA Only - Newegg.com
Lenovo ThinkPad T420 Review: Lenovo ThinkPad T420 review: A 14in business laptop with 2nd Gen Intel Core technology and great features - Notebooks - All Purpose - PC World Australia