I suppose this goes for DLINK DES 3026, 3025 and all its kind. I also wouldnt be surprised if this is defacto for every DLink switch out there.
It is surprising how hard it is, to get to this. By default, its either the TFTP configuration (via a serial cable) or something else.
Set your computer’s static IP to 10.90.90.93 (anything other that 10.90.90.90, but on the same subnet). Subnet mask is 255.0.0.0 and no gateway and no DNS.
check that the switch is reachable by pinging 10.90.90.90. If it is pingable, open 10.90.90.90 in a web browser. My default username was admin and no password.
Reset your switch by selecting reset from the left pane and Reset System from the right pane’s selections.
This should solve 90% of all problems out there.