hi,my son has a wondermedia wm 8650 tablet and think hes changed a setting without realising. we cant connect to wifi, we click on (turn on wifi)and under the wifi networks our network comes up and it says (remembered,secured with WPA/WPA2 PSK) any help please

The wifi connection was previously working and now it is not due to some changes in the system settings. The connection profile might have been deleted that's why the phone can no longer recognize the wifi connection. Your wifi is password protected, the phone cannot connect since it no longer has the password, just try to re enter the password. If this will not help, just set-up again the wifi connections, check this link for a guide http://www.techyv.com/questions/internet-mobile-connection-problem-android

Yeah. Sounds like you simply deleted the password.
Do you know what it is???
depends what you use as a router but most of the times there is a little sticker on the router that has the ID and password...i think...