I'm running main HDD in RAID and all is ok there. I check in BIOS the SSD is recognised - using the Control+I command I can see the SSD is available and status is normal. I boot to Windows 7 and it disappears. I'm running a 550w PSU and wondering if it's a power issue, but why is it not a power issue in DOS? It's puzzling as I previously had it working before until I recently reinstalled Windows 7. BTW, I did edit my Regedit before this so I could change from IDE to RAID on my main HDD. I changed iastorV Start = 0 (THIS IS WINDOWS RAID, HAVE IT ON 0 SINCE 0 MEANS ON) pciide = 3 (THIS IS IDE, HAVE IT ON 3 SINCE 3 MEANS OFF) Before I did this it would get BSOD when starting Windows having only the BIOS changed to RAID on main HDD. Should I have changed the pcide to 3, and instead left it at 0 ? Anyone have any ideas?