As you can see from similar questions asked here, the standard answer is to "reset" to factory settings.
This does not work for me.
I'm not even convinced the thing is actually resetting, since after uninstall of software, removing every trace from my hard drive, manually finding dozens of leftover Sling entries in the Registry and deleting, and rebooting, and resetting the slingbox AGAIN, powered off for an hour, then restart everything, it STILL knows the old slingbox device name and *appears* to accept the old admin password.
Now, I have a legacy box, so it will be different from yours, but really do not count on anything like real help in these forums. I've searched high and dry and am strill dry wishing I were high.
Simply powering off your Slingbox for an hour would not do -- and certain should not do -- a complete reset of any Slingbox to its original out-of-the-shipping-box conditions. I have at least once a year electrical power outages that last longer than an hour -- I certainly wouldn't want to have to reconfigure my Slingbox every time the power failed.
To do a complete reset of your Slingbox, I think the instructions for all of the models that I own say that I must hold in the red button on the back of the SB for 10 to 30 seconds when I power it back up.