oh almost forgot try http://www.tucows.com/preview/195082.html (ping scanner pro) all you do is put in the starting IP for the scan and an eding ip and let it rip ( has alot more features than that but it will do what you want)
i.e. 192.168.1.0 and an ending address 192.168.1.255 if all the boxes use IP's in the range of 192.168.1.xxx
So you assign static IP's to each pc manually, correct? What is the exact message you get about the conflict? How many pc's are on your network? And have you considered using DHCP?