Removed some malware from a HP mini and can't renew the IP address (ipconfig /release, ipconfig /renew), connectivity to router is there. Attempting to renew I get RPC server unavailable. Just connected another (new) laptop to the network with no issues.

Does it currently have a valid IP ?
Also a simple reboot may well resolve your issue.

Reboot has no effect. IP is all zeros, it is when I issue the 'ipconfig /renew' command that I get the RPC server unavailable message.

Try setting a static IP within the nominal range.
Normally that would be 192.168.0.x Subnet 255.255.255.0 with a default gateway of 192.168.0.1

I went back to a previous checkpoint, got connection, and am cleaning up the rest of any infections, one trojan horse so far. I'm good from here for now. Thank you and I will remember the static IP attempt. Thanks,