network dropping

My wireless network ran fine for some four weeks. I have
auto update running for Windows and Norton Internet
security. Last week my network dropped. I have reset the
network which ran fine for 5 days but has dropped again.
One of the machines lost the driver for the d link
wireless adaptor. 3 Pc's run D links wireless adaptors
and 1 laptop a Dell true mobile adaptor. All are set to
ad hoc and on channel 10. No access points used.
Is this an auto update fault?
Please help its costing a fortune having the network
reset in lost business.