Unauthorized wireless access?

[Dogdaysdude]

Is there a way to tell if someone is accessing my WAP that shouldn't be? I'm using XP.
Thanks.

[PrntRhd]

You can look in the router logs for the MAC address (hardware address) of PCs that accessed the router. If it isn't one of yours, it has to be theirs.
It may also be a good idea to change the WAP occasionally even though it is a bit of work to change it in all the accessed PCs.