No Wireless Networks Were Found

hi i have a problem with my Toshiba Qosimio F20 running on Microsoft Windows XP Professional Service Pack 2
I install Kaspersky Pure 2.0 and reboot the PC and the wireless internet stops working, (although i never had such a problem with this PC)
i try to search for wireless networks but non are found in range although if i search using Config Free Program (came with the PC from Toshiba) it finds the networks
What could the problem be ???