Scanning ip range with free lansweeper (problem)

[Frustration]

I have 3 pc's on a network, all three run on windows versions

pc 1 - win 7 pro 64bit
pc 2 - win 7 ultimate 64bit
pc 3 - win vista ultimate 32bit

Firstly do u need lansweeper installed on each of the pc's?

if not my problem is that the only pc that can be seen is the one that lansweeper is installed on, can anyone give me the solution as I tried rescanning but nothing changes.

Thanks in advance

[Hemoco]

If you use IP range scanning, make sure the firewall is configured correctly on all machines, otherwise you won't see the other machines.
http://www.lansweeper.com/kb/The-RPC-server-is-unavailable.aspx

Make the necessary changes and rescan the range again.
You can use the connectiontester in the actions folder to check the wmi access.