I have had a weird problem 3 times in the last week. The 2nd HDD stops working. It just seems to disappear. I can't save files to it, and browsing to it in explorer just gives me the spinning wheel. Reboot fixes it and all is well again - until next time. I use my computer all day every day, so it's a pretty rare problem. I had assumed it was the HDD failing, but there is a similar thread nearby on this forum, and it doesn't seem to question the HDD, but just the MB HDD controllers. My system is set up with windows on SSD, but I have mapped the Users directory onto my HDD. (I do full-time software development, and I didn't want to wear out the SSD.) So when the HDD vanishes, it results in some weird behaviour. But it is coming good again on reboot. I recently (several weeks ago) installed Win 7 SP2, and windows did report a disk failure, but only that once. This week, the HDD has simply disappeared. So, should I run out and buy a new HDD and swap everything over before it fails completely, or should I be looking at a new MB? I'm really not looking forward to spending a week reinstalling a new system.