Error, some other host already uses adress 192.168.100.30
If it says that then I would believe it and investigate your network to find out where it is. Install using a different IP address then ping the address you wanted to use and run arp afterwards to see if it lists a MAC address for that IP.
Just reply with [SOLVED] (or [RESOLVED] if more appropriate) in the subject, as explained in Readme First, and a moderator should come along and mark the head of the thread on your behalf. The current brain-damaged forum software does not allow a user to do so.
Thanks for reporting back. Marking this thread [SOLVED] for posterity.