About Windows 10 product key
When it comes to reinstalling computer, users may concern about its product key. You are afraid that your product key will be affected.
In general, if your product key is activated on the machine, you can skip to input product key during reinstallation and the computer will activate itself. For security, you need to link the product key with Microsoft Account.
To link Windows 10 product key with Microsoft Account, you can go to Settings > Accounts > Your Info. Then, click Sign in with a Microsoft account and follow the prompts.
Once done, you can Go to Settings > Update & Security > Activation to check the details. You should now see a message like Windows is activated with a digital license associated with your Microsoft account.
In addition, if you change significant hardware like motherboard, the computer may not be reactivated after reinstalling.
When to reinstall Windows 10 without CD?
The majority of people are willing to purchase a computer from seller, which comes along with Windows, plus some extra bloatware.
If you reinstall the computer, it will back to factory settings, including all the bloatware installed by manufacturer. During the process, you can choose to keep your personal files or remove everything. After reinstalling, you need to reinstall all the removed apps again.
However, you have to reinstall your computer sometimes owing to system issues, especially when you do not find any useful solutions to fix. In addition, if you think the problem was caused by the installed apps, you still can reinstall your computer.
For reinstallation, you can create an installation media with CD or DVD. But if you do not have CD or DVD, you can create a USB drive with media creation tool or use the built-in feature Reset this PC.
How to reinstall Windows 10 without CD
Method 1: Reinstall windows 10 without losing data
Step 1. Start Reset this PC. You can go to Start menu > Settings > Update & security > Recovery, then click Get started under Reset this PC.
Step 2. Confirm the information in the following picture and click Next.
Step 3. Select Keep my files. This option can keep your files intact. After reinstalling, your files will be back to its original location.
Step 4. View the details as shown in the following picture and click Reset to start the pending operation.
Step 5. Wait and your computer will restart after the operation ends. And you will see an extra folder on the desktop, which is a list for the removed app. You can choose to reinstall the app you will use.
Method 2: Reinstall Windows 10 from USB
If you want to reinstall Windows 10 without CD drive, you can use USB drive.
You can choose to create a recovery drive using built-in tool. But if you want to reset your PC, you should tick back up system files to the recovery drive option. And the USB drive must be at least 16GB in size.
Besides, you can go to Microsoft's Windows 10 download page, download Media Creation Tool and use it to create an installation media according to its instructions. The USB drive requires 8GB in size.
After you create an installation media, you can start to reinstall the computer.
Step 1. Connect USB flash drive to your computer and make sure it can be detected by Windows.
Step 2. Set boot priority to USB flash drive via BIOS, then restart your computer and press any key to boot from USB flash drive.
Step 3. Wait for Windows 10 installation files to load.
Step 4. Set up language and other preference, then click Next and Install now.
Step 5. Click I don't have a product key and Next. It will reactivate itself after reinstallation.
Step 6. Select the operating system and click Next.
Step 7. Accept the license terms and click Next.
Step 8. Select Windows 10 installation type: Custom.
Step 9. Click Drive Options.
Step 10. Delete system partition and other operating system related partitions, and then select the unallocated space to install your Windows.
Step 11. Wait for the final result.
Method 3: Reinstall Windows 10 without CD or USB
If you do not have both CD and USB drive, you can try this way. You do not need any extra devices as long as the computer is bootable and internal hard drive is big enough. Besides, you need to download free version EasyBCD from internet first.
Step 1. Create ISO files with media creation tool
1. Create ISO files via media creation tool. It's similar to creating installation media. The only difference is that you should tick ISO file under Choose which media to use.
2. Rename the ISO file as Windows 10.
Step 2. Create a new partition with Disk Management
1. Open Disk Management. You can press Win + R to summon the Run windows, and then type diskmgmt.msc in the window.
2. Shrink the existing partition and get unallocated space. In the Disk Management page, you can right-click the partition and select Shrink Volume from the content menu, then input 6000 (MB) in the box and click Shrink.
3. Create a new partition. You can right-click the unallocated space and select Now Simple Volume, specify a drive letter for it (H:) and finish the rest of steps based on its instructions. At last, name it as Recovery.
Step 3. Reinstall Windows 10
1. Open the ISO image file, copy and paste all files to the new partition (H:).
2. Open EasyBCD and click Add New Entry.
3. Select WinPE under the Portable/External Media and click the button at the right side of Path to find the new partition (H:), open Sources folder and pitch on boot.win file, click Add Entry.
4. Click Edit Boot Menu and select NST WinPE Image.
5. Click Rename under Modify Menu Entries and rename it as Windows 10 Recovery.
6. Change the number from 30 to 15 next to Count down from option and click Save Settings.
7. Restart your computer and select Windows 10 Recovery in the Choose an operating system page.
8. Follow the Step 4 to Step 11 as shown above in reinstalling Windows 10 from USB drive.
Reinstall cannot solve all problems – how to fix
If you want to reinstall Windows 10 without CD, all above ways can satisfy your needs. Reset this PC gives you a chance to keep your files but you will lose all the apps. And the latter two ways allows you not to delete system partition and other related partitions during the reinstallation and keep the previous Windows in the Windows.old folder on the system partition.
In sum, you need to spend much time in reinstalling programs. To fix it, you can use backup and restore software like AOMEI Backupper, which allows you to create a system image including all files and apps in the system partition. You can restore the entire backup when something goes wrong. After the operation ends, all the files and apps are still on the computer. You can use it as normal.
To create a system image backup, you can download and launch this tool. Then, select the backup type and follow the prompts to finish the rest of steps. At last, you can save it to external hard drive or other storage devices.
To restore backup image from external hard drive, you need to create a bootable drive on a working computer first. Then, switch out the old hard drive and boot your computer from bootable media. At last, connect the external drive included the system image to your computer and restore the image to the target drive.
After you see the following page, click Restore and Select Task or Select Image File, then follow the instructions.
Wrapping things up
You can reinstall Windows 10 without CD or USB to fix system issues. But you will lose all the installed programs. It's annoying.
To fix it, you can create a backup image for your computer and save it to a safe place. Then, you can restore it at any time.
What's more, if your computer is unbootable, you can create a bootable disk or use PXE tool. It can boot your computer and give you a chance to access free AOMEI Backupper, and then restore your computer.