1. Router assigns IP addresses by DHCP, and the one that is not
taken up will be your IP address. Unless another PC uses that IP
address, you will still use that IP address.
If that's your only PC at home, it explains why your IP address
won't change.
Anyway, that is a private IP address, it doesn't matter if it
changes or not. If it's a public one, disconnecting from the Net
and connecting back will change your IP address.
2. What operating system are you using? Do you have administrator
rights on this PC?
3. What did you to make Command Prompt give out this error?
The operation failed as no adapter is in the state permissible
for this operation.