Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

If I leave my pc off for a day, come back to turn it on my HD appears in My Computer and is accessible. But some time later it starts to make a noise as if it's scanning and it disappears from My Computer.

I tried restarting, but that didn't change the outcome. My BIOS settings show that it's there, but nothing on startup or in Device Manager or Disk Management.

It's not my main drive, it's actually my media drive and it's only ever done this since I installed Windows 7 32-bit on my computer. I previously had Windows XP on it.

The hard drive is about 2.5 years old inside a 5 year old computer so I didn't think it was a HD failure so soon, but I don't know a whole lot about computers so it may be that.

The last time I had this problem was when I initially installed Windows 7 on it but I found somewhere online where it said to change the drive letter and it worked after that. I tried that again but it still disappears.

share|improve this question
Perhaps they're driver changes? – digitxp Aug 13 '10 at 3:28
Have you checked the drive's SMART readings, this will allow you to rule out hardware failure. Check this question for how to do this. – DMA57361 Aug 13 '10 at 10:39

Download the manufacturer's drive diagnostic (or use the Ultimate Boot CD), and run the diagnostic. If this is an internal drive, it might be starting to go on you. If it's an external drive, the USB controller on the enclosure might be going.

share|improve this answer

I'm an IT tech and I'm having the exact same problem as you. I also have Windows 7 x64 and have done some testing with this issue. I tried new power supply, new drives, new everything and discovered that the actual port itself was the issue. No matter what drive I plugged into that port, out would do the exact same thing. I have P67a-GD55 mobo and it seems that my Port 4 is faulty. I even had it replaced with a new motherboard and less than 2 months later, the same problem occurs.

Some useful information for anyone else having similar problems and come across this thread. Intel recently did a recall of motherboard with 6-series chipsets because of issues with the sata ports.

share|improve this answer
Was this the one where a 6gbps port would slowly deteriorate? – Journeyman Geek Nov 21 '12 at 12:09

Sounds like a sleep state issue.

See if it's set to go into sleep mode in Windows Power Management Options.

Check for firmware updates on the manufacturer's site, & maybe even a Win7 driver.

One of mine recently went blank after similar behavior after only 1 year of use, it became sketchy, passed tests & had it's updates and I still lost over 1TB. Not fun.

share|improve this answer

It could be a power issue. Check if your hard drive is still running while you can't see it in Windows anymore. In my case, one hard drive would occasionally restart (I could hear the platter spinning up). After restart it was running but it simply wasn't picked up by Windows. The issue was the video card drawing too much power and causing the hard drive to shut off. I fixed the problem by not playing games and then by buying a higher rated PSU.

share|improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .