I have Win 7 Home Prem. I have multiple disk drives two are hard drives. Windows sometimes looses site of my second hard drive meaning I cannot get program access to the drive nor see it in COMPUTER. The problem is solved by rebooting. I am not sure why but I think it my be related to the fact that I have INCLUDED folders from my 2nd hard drive into MY PICTURES and MY Music. The problem seems to occur more freqauently and unexpectedly --- therefore I am not able to pin down the actual circumstances or actions leading to the problem

If it's happening more and more frequently it sounds more like a pending drive failure than a Windows problem. Make sure all of your important data is saved someplace else then download and run the drive manufacturer's utility to check the drive for errors.

One of my hard drives exhibited this behaviour. You might be able to use "Disk Manager" to "Rescan Disks" instead of having to reboot to see the drive. I removed the offending drive from my system since it was only 80 or 120 GB (don't recall which) in size. I replaced it with two 2TB drives. By the way, the spelling is "sight", not "site". I'm not sure about the spelling of loses either.

What is the model of your computer? I suggest you access the website of the computer or motherboard manufacturer, download chipset, SATA driver and BIOS updates. Install them into your system.Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.