I just installed Splunk on a Windows 10 machine and when I start it I get:
I tried modifying my firewall but that didn't solve the issue. I was thinking it might be a port forwarding issue but if so, what addresses and ports do I need to forward?
open services in windows,
open windows search and type services, you should see splunkd service in services, check whether the service is started state or not. if not start the service.
once services is started open any browser and type http://localhost:8000 this is default address of Splunk web.
let me know if this helps.