Arduino wifishield after a while error problems

Hi everyone,

I have a problem with the arduino wifishield, i have the example code running and after a while (sometimes after a day and sometimes after 2 days) the error led is on. If i reset the arduino the arduino is connected again with the SSID and password of my network. I try diffrent wifi networks.

which shield?

provide a link

A arduino Uno rev 3 and a wifi shield R3.

Uno: Arduino Uno Rev3 — Arduino Official Store
Wifi: Accessories — Arduino Official Store

Your PC may have put the USB port to sleep.

There is no pc connected, the arduino is standalone connected to an 13v 2Amps power suply connected to the vin.