belkin usb adapter to linksys router

I'm completely baffled now. I have a Linksys router/modem connected by
cable to PC1(xp) and everything works fine.

Then I bought and installed the Belkin USB wireless adapter on
PC2(winme) and that saw both PC1 and router fine....however this has
since stopped and neither the router or PC2 can see each other or
connect to each other. PC1 still works great.

I'm such a simpleton that this is driving me round the bend. I'm not
sure what other info i could include, but any help or advice would
really be appreciated.

Thanks