Old dell laptop

Recently acquired a old dell insprion | 5150 laptop, in a good condition, and I am able to charge it.

Yet now after my sibling messed around with it, it is having issues booting up with the hard drive or like, it's bootable device isn't working (As my sibling tried to use it's hard drive in a tablet pc)

But I am hoping that I can fix it, and use it, not as my main laptop but maybe for funises or to give it to someone who needs one, but the latter less likely as I don't think anyone really wants a old chunky laptop. Exception being me and computer freaks ;^P 

Anyways I was thinking about putting tinycore on it or debian, it did have a old windows on it, xp I believe, and on the back there is the product key, if like anyone wants it? I don't completely know how MC Windows installs work but product keys are important to it I believe.

Also, if anyone has experienced something simliar, and overcame it, let me know how you did it!