Dangerous amateur here. I connected my new RB751U-2HnD via lan and successfully logged in made a few changes then when I tried to get back in with new Ip address it could not connect. I have pushed reset a few times, powered down but nothing comes up in the browser. It looks like it has connected to the default Ip address but the screen is blank. When I go to my wireless connection after turning off LAN I can see the router there still nothing re: accessing software. I'm running Windows 7 and tried on an XP machine as well but still nothing. I should also mention that ping comes back negative. Any thoughts?

Try winbox, discover and connect by mac address.

Try winbox, discover and connect by mac address.

+1 to that... if that doesn't work you can always netinstall it.

Still a blank screen. Here is the result of ipconfig. When this problem happened I was trying to change address from default to 192.168.10.50. I've tried both addresses as well as resetting the board. When I use ping the addresses there is no reply. Once in a while I will get destination host unavailable message.

Still a blank screen. Here is the result of ipconfig. When this problem happened I was trying to change address from default to 192.168.10.50. I've tried both addresses as well as resetting the board. When I use ping the addresses there is no reply. Once in a while I will get destination host unavailable message.

You made IP 192.168.10.50 on MikroTik? And no bridge?
Check every port for connection, and by the way, I think IP of your PC should be in 192.168.10.0 subnetwork...