Why does my laptop only connect to Wi-Fi after restarting?

When a laptop only connects to Wi‑Fi after a restart, the most common cause is a driver or power-management issue: the wireless adapter may not wake or reinitialize correctly after sleep, hibernation, or a low-power state.

What’s likely happening:

• Fast Startup can preserve some system state instead of doing a fully clean boot, which can leave a bad network state in place.
• Power management may let Windows turn off the Wi‑Fi adapter to save power, and the adapter may not recover cleanly.
• Corrupted or outdated Wi‑Fi drivers can also fail during sleep/wake transitions.

Most effective things to try on Windows:

1. Disable power saving for the Wi‑Fi adapter

   • Open Device Manager → Network adapters
   • Right-click your Wi‑Fi adapter → Properties → Power Management
   • Uncheck Allow the computer to turn off this device to save power
   • If this Power Management tab isn’t available, your system may not expose that option in its current standby/power mode.

2. Turn off Fast Startup

   • Open Control Panel → Power Options
   • Choose What the power buttons do
   • Select Change settings that are currently unavailable
   • Uncheck Turn on fast startup

3. Update or reinstall the Wi‑Fi driver

   • In Device Manager, uninstall the wireless adapter, then restart so Windows reloads it on boot, or install the latest driver from the laptop manufacturer or Wi‑Fi chipset vendor.

If those steps don’t fix it, the problem could be the adapter hardware itself, other Windows power settings, or less commonly the router/DHCP side. If the issue only happens on one network, checking the router is also worth doing.