To fix a WiFi disconnect error on a Windows PC, try the following steps:

1. Restart the router and PC: Turn off the router and PC, wait for a few seconds, and turn them back on. This can resolve temporary issues with the connection.
2. Check for driver updates: Go to the manufacturer’s website and check if there are any updates available for your network adapter driver.
3. Disable power management for the network adapter: a. Right-click on the Windows Start button and select “Device Manager.” b. Locate the network adapter, right-click on it, and select “Properties.” c. Click on the “Power Management” tab. d. Uncheck the “Allow the computer to turn off this device to save power” option. e. Click “OK.”
4. Disable fast startup: a. Type “Control Panel” in the Windows Start search bar and press Enter. b. Click on “Power & sleep.” c. Click on “Additional power settings.” d. Click on “Choose what the power buttons do.” e. Click on “Change settings that are currently unavailable.” f. Uncheck the “Turn on fast startup (recommended)” option. g. Click “Save changes.”
5. Reset the network adapter: a. Open Command Prompt as administrator. b. Type “netsh winsock reset” and press Enter. c. Type “netsh int ip reset” and press Enter. d. Restart the PC.
6. Disable VPN: If you are using a virtual private network (VPN), try disabling it and see if the issue persists.

If the issue persists after trying these steps, contact your Internet Service Provider (ISP) or the manufacturer of your router for further assistance.