No error code? Start here.

What do you see?

Choose the closest symptom. Each page helps you narrow down the cause and points to step-by-step guides; it is not a diagnosis.

It turns off, reboots or stops responding without warning.

Windows shows a blue screen and restarts.

No picture, a blinking cursor, or the screen goes black in games.

A startup message, beeps, or no Windows desktop.

A game closes, the display driver resets, or a DLL is missing.

Connected but no internet, DNS errors, or Wi-Fi is missing.

An update shows an error code or will not install.

USB, Bluetooth, printer, sound or the graphics card shows an error.