Hard Drive not being recognized

It will shows up in diskmgmt as unallocated space,
but not in my computer.
This was given to me from my brother, and he used a mac air book.
Is there any way to access.

you need to create a partition and format it and make sure to mark it as active in disk management

Which size is the HD? Some motherboards doesn't recognize properly HD's over 1TB... If this is your case, you could try to update your Bios (is risky), r you can get a program like Paragon Partition Manager, you'll be able to format and create the partition, if the HD is correctly pluged on your pc.

its 250 gb...i was told it wouldn't recognize it because it is formated with a mac file system and was wondering if there is a way to get around this.