No Wireless Connection Found

I have an Inspiron laptop.  It was simple to set up on a wireless basis with my router/modem a few months back.  Now, it only works when I hook it up directly to the router.

I don't know what has happened to change it.  The icons at the bottom right of the screen indicate my linksys system is full power.  When I check for connections it says InterPro is "low power".  And when I check "find wireless networks" it says: none found, "you must have someone else managing your network."  (It used to be that I found my linksys network and other networks in the neighborhood.)

I have run adaware and spybot and, oh, I also checked to see that "wireless access" is "on."

Any suggestions?