If you run into problems with your PC, a USB recovery drive can help you troubleshoot and fix those problems, even if your PC won't start.
Your PC might have come with a recovery image that's used to refresh or reset your PC. The recovery image is stored on a dedicated recovery partition on your PC and is typically 3-6 GB in size. To save space on your PC, you can delete the recovery image from your PC and use a recovery drive instead. Windows 8.1 includes a built-in tool to create a USB recovery drive. Windows will let you know how big the recovery partition is, and you'll need a USB flash drive at least that big.
Creating a recovery drive will erase anything already stored on your USB flash drive. Use an empty USB flash drive or make sure to transfer any important data from your USB flash drive to another storage device before using it to create a USB recovery drive.
Before you create the recovery drive, you should check if your PC has a recovery partition. If it doesn't, you can create one and then create the recovery drive.
Swipe in from the right edge of the screen, then tap Search.(If you're using a mouse, point to the top-right corner of the screen, move the mouse pointer down, then click Search.)
Enter Command in the search box, swipe down on or right-click Command Prompt, and then tap or click Run as administrator.
You might be asked for an admin password or to confirm your choice.
Enter recimg /showcurrent, then press Enter.
If you see an error message stating "There is no active custom recovery image" you will need to create one before you can create a recovery drive.
You should only create a recovery partition if you don't currently have one on your PC.
To create a folder for the recovery partition, enter mkdir C:\RefreshImage, and then press Enter.
To create the image in the folder you just created, enter recimg -CreateImage C:\RefreshImage, and then press Enter.
Enter recovery drive in the search box, and then tap or click Create a recovery drive.
After the recovery drive tool has opened, make sure the Copy the recovery partition from the PC to the recovery drive checkbox is ticked, then tap or click Next.
Insert a USB flash drive into your PC that is at least as large as the size indicated on the screen.
Tap or click the USB drive you would like to use for your recovery drive, then tap or click Next.
Tap or click Create.
The recovery image and necessary recovery tools will be copied to your USB flash drive, which will take a while depending on your PC and the size of the recovery image.
When the process is finished, do one of the following:
If you want to keep the recovery partition on your PC, tap or click Finish.
If you want to remove the recovery partition from your PC and free up disk space, tap or click Delete the recovery partition. Then tap or click Delete. This will free up the disk space used to store your recovery image. When the removal is finished, tap or click Finish.
Remove the USB flash drive.
This is now your Windows 8.1
recovery drive, and you'll need it if you ever need to refresh or reset your PC. Keep it in a safe place and don't use it to store other files or data.