Help! wireless network not supporting 8 computers!

[slic]

I have recently taken over as a teacher at a small charity ran centre which has a BT business home hub with 4 desktops and a maximum of 5 laptops which should be able to run off it wirelessly.  The broadband line is fine and so are the first four computers that are connected wirelessly.  After this the laptops which have been switched on one at a time have limited or no connectivity to the internet. 

Surely a wireless network should be able to support this amount of computers.  When the computers are individually connected by ethernet they work fine. 

Im seriously struggling to solve this problem if someone could help please.

The solutions I have came up with are: a) connect all computers by ethernet but this should not have to occur

b) upgrade the box or get a signal extender as the box is G not N rated. 

the centre is housed within a church hall so ethernet and trunking and cabling is not a viable option.  I have also changed the channel in case of interference on numerous occassions and this is not working either.

[MHC]

Is it a Business Hub or Home Hub?    they are different devises.

The business hub - 2700 HGV or 2701 HGV will cater for 5 wireless devices - previously I have a 2700 coping wiyth around 10 and now a 2701 with about 15.   Never a problem.

You should not need to connect all of them via ethernet

Upgrade the box as it in G not N rated - what a load of tosh (I am being polite).

To me it sounds as ifteh password has been changed or MAC registration has been enabled.  

I would suggest - go to each laptop and delete and profile that might be tied to the hub.

Reset the hub to default after noting any key settings.

Restart the hub and register each laptop (MAC address) one at a time and ensure the password is EXACTLY correct.

[slic]

Ive done all of the above !! no change I'm no thick (im being very polite!!)