I take it you were able to boot from the Windows 8.1 install disc and do the install, right? If so, that would tend to suggest there's something about that SSD that could be the problem. Are you sure you installed the right driver(s) for it? Try installing Windows on that hard drive and see if you can boot from that. If that doesn't work, I'd run memory diagnostics (you can download them from the MS web site). You could also make a Linux boot disc and see if that works. I like the Mint version of Linux that you can download from
http://www.linuxmint.com/download.php . You'll get a .ISO file that you can burn to a DVD, boot from the DVD, and be up in running without having to install anything. The user interface looks enough like Windows that you should be able to use it with little effort to look around at your system and see what's working and what's not.
Good luck.