I recently installed Windows 10, making sure not to remove any of the existing partitions (the hidden Reserved partition, the System partition, the Primary OS partition, and the Recovery partition) by formatting the Primary partition containing Windows 8.1 first and then installing Windows 10 to that partition. After the upgrade I found that I could no longer restore the Intel Compute Stick to the factory install of Windows 8.1 with Bing because the F8 options were not aware of the existence of the recovery partition.
The recovery partition (partition 4) is an 6.35 GB NTFS formatted partition labelled 'Images' that contains images of the Windows Recovery Environment (Winre.wim) and the Windows 8.1 with Bing installation with slipstreamed Intel and Realtek drivers (install.wim) using the following directory structure:
-- Windows Images
In order to restore the F8 functionality, Windows needs to know the location of the Recovery Environment and Installation image files. To verify and restore, you can do the following:
From an Elevated Command Prompt (Run as Administrator) type:
You should see entries similar to the following:
Windows Recovery Environment (Windows RE) and system reset configuration
Windows RE status: Enabled
Windows RE location: \\?\GLOBALROOT\device\harddisk0\partition4\Recovery\WindowsRE
Boot Configuration Data (BCD) identifier: 243cc8c6-43d5-11e5-ad26-fc1eb68e9aac
Recovery image location: \\?\GLOBALROOT\device\harddisk0\partition4\Windows Images
Recovery image index: 1
Custom image location:
Custom image index: 0
In my case the Recovery image location was missing. To fix this, I ran the following command:
C:\Windows\System32\Reagentc.exe /setosimage /path "\\?\GLOBALROOT\device\harddisk0\partition4\Windows Images" /index 1 /target C:\Windows
This allowed the Windows Recovery Environment to locate the Installation image and I was able to reset the Compute Stick back to the factory defaults using F8.
Just FYI, if you want to view the Recovery partition, you can use DISKPART to temporarily ASSIGN a drive letter to the volume and then REMOVE it when you are done. You'll need to uncheck "Hide protected operating system files" to see the install.wim image and you'll need to reassign permissions to give your user account read access to the Winre.wim image. You can copy these to a USB drive if you want to use to them to recreate the recovery partition in case you inadvertently remove it.
More information about recovery images can be found here:
On a related note, if you want to pull the product key for your copy of Windows 8.1 with Bing from the Compute Stick's BIOS, you can use the utility ProduKey.