Intermittent lack of internet access, please help!

miamoo

I'm having problems connecting my laptop to my router, sometimes it connects fine, other times it connects but then says 'unrecognised' and wont let me go on the internet. I also have a netbook and I never have a problem with his.
I have taken the laptop to the repairer and there is nothing wrong with it, it worked fine when he had it, but the problem is only occasional so hard to show someone.
Does anyone have any idea what it could be?

miamoo

Can anyone help?

macman

More info: make/model of laptop, ditto router, what OS are you running?
How are you trying to connect-wireless or ethernet?
if the former, does the same problem occur when you try to connect by ethernet?
Can your laptop see the router, can you detect your own network?
First thing to try is to log into the router's web interface and change the wireless channel.