What is this disk?

[Mysteryman2]

Wasn't sure where to post this question!

A disk has appeared on my PC - it is listed in File Explorer as H:, but, cannot be expanded to see content.

I am pretty sure it is since my son was home and connected his laptop to the home network (by WiFi) and I suspect that my PC has detected it and very (un)helpfully given me access to it.

However, he and his laptop are no longer here and certainly not connected to network anymore. But, the disk remains listed! It also appears on Disk Management as a partition of my C: drive. I was hoping to include an image of Disk Management screen, but, cannot work out how to.

If I right-click on the entry in File Explorer then there is nothing that looks like it will let me eject/unmount it.

Anybody got any ideas of how I can remove it from my system?

UPDATE
Just noticed that it is actually small (450MB) and probably nothing to do with son's laptop (I misread and assumed it was 450GB!)

The Disk Management page says "450MB NTFS Healthy (OEM Partition)

....and it wont let me delete it!

 

[USAFRet]

Show us a screencap of your Disk Management window.

 

[rusabus]

This probably appeared after your computer applied the 1803 update to Windows 10. It's a pretty common issue. You can remove the drive letter with mountvol from an elevated command prompt. Here's how:
1. click start and type cmd in the search area
2. Right-click on "Command Prompt" and click "Run as Administrator"
3. In the command prompt window type the following:
mountvol h: /d
4. press enter

You probably don't even have to reboot.

 

[geofelt]

If this is a pre built pc, what you see is likely a recovery partition that the unit's bios can use to recover the pc to it's original state.
450mb seems about right for that.

 

[USAFRet]

UPDATE
Just noticed that it is actually small (450MB) and probably nothing to do with son's laptop (I misread and assumed it was 450GB!)

The Disk Management page says "450MB NTFS Healthy (OEM Partition)

....and it wont let me delete it!

As suspected.

You don't DELETE that partition.
Rather, you just remove the drive letter.
Disk Management, Right click, Change path or drive letter, Remove.