Format what? The D partition with only 55MB space? If its not used, sure. But sometimes these partitions are used for recovery purposes.
Since you bought a new pc with this condition, i do advise you to go back to the store/place you bought it and discuss it.
However, in any case you should be able to see the majority of the space of the harddrive, if that's hidden to you that's probably an unintended issue.