Ownership , thats the trouble with 2nd, 3rd hand pc's,
You now think its warm so why buy it?, what changed your mind?
on the subject who it was originally , open control panel click system
check who its registered to, should give you a clue unless its oem.
Anyway check the keyboard, if its got German characters an English install just gets too confusing as the keys are too different to be bothered with.
Take more care in the future .
interesting news today for the paranoid