Parition ("E drive") suddenly went missing. Does not appear in Windows Disk Management tool or third

In my Sister's laptop, running Windows 7 Ultimate x86, all of a sudden, while she was working on the computer, the "E drive" went missing which was a partition on the hard disk (I don't remember if it was a logical or primary partition). She tried restarting the system but to no avail. So, I told her to open the "Disk management" tool in Windows 7 to see if the partition is visible in there. I did this because sometimes, in my computer, my expansion drive wouldn't show but it would be visible in the disk management tool and all I had to do was to re-assign it a drive letter. But, in this case, it wasn't visible over there.

So, now I told her to download "Mini-Tool Partition manager Home edition" and install it on her laptop. On running it, it wouldn't show the partition either. It would just show "C:", "D", "System Reserved" and unallocated space.

However, when I added up the size displayed by C:, D:, System Reserved and Unallocated, it doesn't add up to the actual hard disk size. It means the partition is somewhere there but not visible.

Is it possible that the partition would show up correctly if the laptop is booted into the bootable image of Mini-Tool Partition Manager? Any other ideas? :(


Microsoft MVP
Staff member
Premium Supporter
Microsoft MVP
You may find that the total size you have calculated is different from the actual size of the physical drive due to various issues due to hardware and software manufacturers using different values to interpret the meaning of 1Kb ( 1000 an 1024), 1Mb (1000 x 1000 and 1024 x 1024) etc. There may also be hidden partitions adding to the difference. It would help if you can show an image of the drive as shown by the Control Panel Computer management tool.


Excellent Member
Microsoft Community Contributor
You are saying the missing partition is on the primary hard drive and not on some type of external drive or virtual drive?

The mini-tool can, I believe, hide partitions but it should still show as a partition in the mini-tool.

Could your sister, or someone else have deleted the partition accidentally?

If the unallocated space is the old partition, the mini tool, or perhaps another utility, might be used to try to recover the partition. It might work, but you may get only one chance before the data is overwritten.


Extraordinary Member
Premium Supporter
Sometimes the partitions cause trouble. Like I couldn't get Windows 7 installed instantly / or by MiniTool BUT I could get the thing done by GParted, GParted -- About

Like patcooke writes, there may be hidden partitions. Go figure, and I trust the best way to approach it is via BIOS. Most probably Windows is blind? Windows may awaken by start-stop-start-stop etc... but you never really know. Probably your best option to find all partitions is in BIOS.

One thing is, of course, to nullify CMOS. Either by taking the jumper off / reconnecting it, or by taking the battery out / putting it back. Unlikely, I think, but possible.

Thank you for all the replies! Since she isn't over here and is far away, and also considering the fact that she isn't a tech-savvy person and thus, is unwilling to fiddle with the hardware/complex software settings, there isn't much that I can do right now. But really, thanks for your help. When she'll be visiting us in August, then I'll look into it and follow the tips provided here. Till then, thanks and take care!


Extraordinary Member
Premium Supporter
If you have a good relation to the seller, contact them. They do have the expertise.

Best wishes, all you "Jolly good Fellows". :)

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