I've installed a new SSD as a secondary drive and it has worked for two days. At the moment, I can't see any mention of it in Computer (Windows Explorer) but the BIOS detects it.
There is a screenshot below of the disk manager, I believe Disk 2 should be the 120GB Intel X-25M G2 SSD:
Also, ignore the 8GB drive listed there, it's just a harmless USB.
How do I fix this? I don't have any data worth keeping on it so I'm quite happy to get a blowtorch and format the drive if needed.