If you have connected this system to a local network that uses DHCP, it will have grabbed an address off that network. Even if you disconnect from the network and power cycle - the system will stay on the last IP it had. I just set one up at my shop - then took it to the job site and installed. I was surprised that even after a couple of reboots - it stayed on the IP it had used at my shop - rather than returning to default.

You need to first figure out what IP this thing is on. Access programming from one of the phones (page 1-2 in the SL1000 programming manual will tell you how to do that) and check program 10-12-01. That will show you the current IP. Then, assuming your PC is on the same network - you should be able to enter the phone system IP in your browser address bar and - you're in.

FYI - I use IE for the browser. I've found that WebPro won't let you do certain things if you use Chrome. Haven't tried any others......