To allow access only for network computers u need to do this:
Put wampserver in offline mode.
Open C:\wamp\bin\apache\Apache2.2.11\conf\httpd.conf and search for the line "Allow from 127.0.0.1"
Run this command in command prompt( start>>run write cmd, press enter), "ipconfig", here u can see your local area network IP, it's the one like 192.168.....
In httpd.conf after the "Allow from 127.0.0.1" line add a new line "Allow from 192.168.." (your LAN IP)
Restart Apache server, wamp server .. apache >> service >> restart service
And that's it.
What you've done is that u allow access to server only on localhost and LAN
Remember that if you put wampserver back online that line won't disappear so on online mode u will actually have access only on LAN, so delete the line if you want access from everywhere