Lenovo ThinkPad T420s

BIOS hotkeys

• BIOS Setup: F1
• Boot device select: F12

Windows XP compatibility

T420s is one of the last laptops natively supporting Windows XP. All drivers are available on Lenovo website.

WARNING

Before installing Intel Graphics Driver, you need to manually install Microsoft .NET Framework 3.0 for Windows XP.

Windows XP installation

Vanilla Windows XP SP3 install media does not contain SATA drivers for T420s controller. I did not want to use modified install media, so i used Easy2Boot wrapper method successfully.

Windows 11 compatibility

After upgrading RAM to 2x4GB set i managed to install vanilla Windows 11. After tinkering with some extra drivers for screen brightness hotkeys, all features i care about work great. It's not an effortless daily driver as of 2024, but as a supplement to a modern desktop machine, and a travel companion, it can do productivity and light programming reasonably well.

USB-C charger adapter

Original charger is 20V, which is one of the native voltages of USB-PD. There are adapters available to charge ThinkPads with USB-PD chargers and power bank supporting 20V natively.

WARNING

Do not use USB-PD power sources not supporting 20V natively e.g. Nintendo Switch charger HAC-002 that can only do 5V and 15V. When connected, Windows does not report battery state as charging and laptop makes an unhappy high pitch whine.

Storage upgrade

T420s (s stands for slim) is limited to 7mm thick SATA disks. Most modern SSDs are 7mm, but make sure to check before upgrading.