ok lol 2 things
i am not an expert at this stuff lol...but,
the reason why you your ip's are changing is because u do not have a static ip. talk to your internet provider with getting a static ip.
and second,
there is a program on windows xp that you can use which is similar to MS DOS
first go to Start-->Run then type in: Command, then you could do w/e there lol.