I've posted these script b4 but not as good as richgill's but I notice richgill's link that there's a problem when the user logs to WinME or 98, I believe it was design primarily for domain pc/users.
Try this:
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From the command prompt.
c:\>FOR /L %i IN (1,1,255) DO ping -a 192.168.0.%i then Enter.
(1,1,255) - (start,step,end) and %i is the variable.
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If you want the sesult to be in a file. (ping.txt)
c:\>FOR /L %i IN (1,1,255) DO ping -a 192.168.0.%i>>ping.txt
(1,1,255) - (start,step,end)
%i - variable.
ping.txt - Resulting file.
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I've got this link from SteveTheGeek.