the netconfig.bat is a backup of your internet settings, this was made when you downgraded(you CAN delete it if you want). And for your internet not working its because you have a custom xmb or you use the hidefile prx.If you are using a custom xmb try flashing your normal one, then use cxmb.If you are using hidefile, turn it off by pushing start. If it is something else then im not sure if i can help you.
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