Instructions
Fix DNS Error
Look at the top of your PSP and make sure that the WLAN switch is positioned to the right. Turn the switch to the right if it isn't.
Manually input both the IP address and SSID of your router when configuring the PSP's Internet settings--as opposed to selecting "Automatic."
Retry inputting the router's WEP (wired equivalent privacy) key during the PSP's Internet configuration process and check to make sure you input it correctly. It is often the case that people simply input an incorrect WEP key during the initial configuration attempt.
Consult your router's user manual to reset the WEP key.
Contact your ISP (Internet Service Provider) concerning the DNS error if none of the above steps solve your problem.