The Unmountable Boot Volume blue screen could be caused by a number of things. Scan the RAM in the machine with a bootable piece of software called Memtest which can be downloaded here: http://www.memtest86.com/memtest86-3.5.iso.zip If it finds errors, then the RAM is faulty and needs to be replaced. If not, the it may be the hard drive is failing/failed. This will need replacing. Try another drive in the laptop and see if that fixes anything.