Is there any way to change this icon:
by this:
?
Thanks
Find the folder "Documents and Settings\<user name>\Application Data\SolarWinds\NetworkAtlas\Maps\Orion\localhost\NetObjects\User Graphics" on the machine where the Orion is running and you should see the file containing the picture there (if you started the Network Atlas at least once on this machine). Duplicate the file containing the lightning picture and add "-up" to its name. So for instance if it is named lightning.gif, duplicate the file and name it lightning-up.gif. When the file is created, start the Network Atlas application on the machine so the picture gets into the database.
You can also add different pictures for other statuses, and name it like lightning-down.gif, lightning-warning.gif etc...
Is there any way to set a transparent background to this icon ?
Network Atlas supports GIF transparency, so if your icon is in GIF format, then it should work.