Hi there, I am currently trying to fix a friend's 2012 13" Macbook Pro that is having several issues. The main issue is that it simply won't launch any system applications. For example, Safari instantly says it 'closed unexpectedly' and Finder won't launch a window. Sometimes, finder won't even start upon boot. It is even as deep as system processes, as it no longer mounts any external disks or connects to WiFI. He has reinstalled OS X Yosemite twice from recovery, which took an exceptionally long time. Although, this was done without a reformat to prevent the loss of data, since no backups can be made due to it not mounting external disks anymore. When we booted into safe mode, it still took quite a while to boot and still wouldn't mount a disk. Any thoughts on what could be causing it? The main priority is getting data off currently, and only want to remove the hard drive and connect it to another as a last resort. Thanks in advance for any suggestions!