A Re-occurring Problem

I have been having a problem with my 'Netgear' wireless adapter . I
communicate to cable internet with the Netgear. Lately, out of the blue I
occasionally lose the softwear from my computer which is a Dimension 8400.
It always happens after a shutdown, it is missing on startup.

I reinstall the softwear using the cd that came with it. Everything will be
fine till it disappears again.

Anyone have any ideas why this is happening? My cable wires are all new.

Would it be better or easier to try a system restore? Can it restore a
missing softwear?

TIA
Wull