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Rebuild Your PC

Start fresh with a clean install of Windows 10

One of my nieces recently crashed her Dell XPS laptop. When it would boot up, it would present a Bitlocker screen and ask for a key to be entered. I'm not a user of Bitlocker, and she had no recollection of activating Bitlocker or of any key, so after some basic troubleshooting, we decided it was time for a fresh start.

There are several ways to reset a functioning PC, including "Reset your PC" and "Fresh Start". These options and their behaviors have changed over time in various versions of Windows 10. Some of these options may let you keep some of your files. If you want to explore that route, I would recommend reading up on each option separately.

In this scenario we are going to do a clean install. Yes this will completely wipe the hard drive, but if you are using Microsoft OneDrive as your primary data store for personal files, they will all be retained and available (from the cloud) after the clean install. Installed applications will not be kept.

Preparation

  • Get a USB drive at least 8GB in size.
  • Go here: Windows 10 Download
  • Click on "Download tool now". Run the app. Note that you can run this on any PC. It doesn't have to be the one you plan to do the clean install on.
  • When you are prompted with "What do you want to do?" Select "Create installation media" (not "Upgrade this PC now").
  • Select "Use recommended options for this PC"
  • Select USB flash drive, then select the drive letter of your 8GB USB drive.
  • The Media Installation app will then configure the USB drive as a bootable drive for installing Windows 10.

Start the Clean Install

  • You now need to reboot the PC from the USB drive instead of your primary hard drive.
    • The procedure for this varies by manufacturer. For Dell, keep clicking the F12 key during the reboot process and you will be presented with a boot screen that allows you to select the USB drive.
    • You could also change the boot drive in your BIOS (press F2 during reboot), but this is more complicated.
  • After you specify that you want to use the USB drive the PC will reboot and start the clean install process.
  • You will be prompted with a series of screens for simple configuration choices. Accept the license agreement, etc.
  • When asked "What type of installation do you want", select "Custom: Install Windows only (advanced).
  • The next screen will be about hard drive partitions.
    • You only want to modify the partitions on your main, OS drive, likely called Drive 0. If you have multiple drives in your PC make sure not to change them.
    • Delete all the partitions on the main OS drive. Select "new" to add back one partition. You will get a message that says "Windows might make additional partitions..." This is fine. You will end up with 3 partitions in the end, your main OS partition which is assigned the majority of the space and two small utility/recovery partitions.
  • The installer will then proceed through a series of steps and then reboot.
  • You will be presented with more configuration screens.
    • Choose appropriate language, etc.
    • When asked for Microsoft Account or local account, use Microsoft Account.
    • Connect to your network.
    • I strongly recommend enabling OneDrive.
    • I generally decline most of the advertising and tracking options.
    • Set a PIN number.
  • The PC will reboot again and then you will prompted to log in with your PIN or Microsoft Account.

You now have a PC with a clean, factory install of Windows 10!

What's Left

  • Download and install Chrome and/or Microsoft Edge.
  • Most of your basic drivers will be installed, but I'd recommend installing drivers recommended by the manufacturer.
    • For Dell, go to: Dell Support
    • In Search Support, enter your Dell Service Tag. There will be a sticker on your PC with the 7 character value (it should also be in your BIOS).
    • Select "Drivers & Downloads"
    • I generally don't install everything shown, but rather I install the "Dell Update Application" and install what it suggests.
    • Make sure to update your BIOS if it's out of date.
  • Install other software as needed (office.com, Nvidia, etc).

Common Questions

  • Do I need my Windows key?
    • If you are doing a clean install on an existing PC, like a Dell in this case, no you don't need a Windows key. Microsoft will figure it out based your Microsoft Account and the PC hardware configuration.
    • If you are building a new PC from parts you will need a Windows key.
  • How do I find my Windows key just in case?
    • I've put a small VB script at the end of this article that will pull the key from the registry.
  • How long does this take?
    • About 30 min to create the USB install Drive.
    • About 45 min to clean install, assuming you have an SSD drive

Appendix - How to Get Your Windows Key Value

Save this script to a file and your desktop named "key.vbs" and run it.

Dim objshell,path,DigitalID, Result
Set objshell = CreateObject("WScript.Shell") 
'Set registry key path 
Path = "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\" 
'Registry key value 
DigitalID = objshell.RegRead(Path & "DigitalProductId") 
Dim ProductName,ProductID,ProductKey,ProductData 
'Get ProductName, ProductID, ProductKey 
ProductName = "Product Name: " & objshell.RegRead(Path & "ProductName") 
ProductID = "Product ID: " & objshell.RegRead(Path & "ProductID") 
ProductKey = "Installed Key: " & ConvertToKey(DigitalID)
ProductData = ProductName & vbNewLine & ProductID & vbNewLine & ProductKey
'Show messbox
MsgBox ProductData & vblf & vblf, vbOk, "BackUp Windows Key Information" 'Convert binary to chars 
Function ConvertToKey(Key)
Const KeyOffset = 52
Dim isWin8, Maps, i, j, Current, KeyOutput, Last, keypart1, insert
'Check if OS is Windows 8 
isWin8 = (Key(66) \ 6) And 1
Key(66) = (Key(66) And &HF7) Or ((isWin8 And 2) * 4)
i = 24
Maps = "BCDFGHJKMPQRTVWXY2346789"
Do
Current= 0
j = 14
Do
Current = Current* 256
Current = Key(j + KeyOffset) + Current
Key(j + KeyOffset) = (Current \ 24)
Current=Current Mod 24
j = j -1
Loop While j >= 0
i = i -1
KeyOutput = Mid(Maps,Current+ 1, 1) & KeyOutput
Last = Current
Loop While i >= 0
If (isWin8 = 1) Then
keypart1 = Mid(KeyOutput, 2, Last)
insert = "N"
KeyOutput = Replace(KeyOutput, keypart1, keypart1 & insert, 2, 1, 0)
If Last = 0 Then KeyOutput = insert & KeyOutput
End If
ConvertToKey = Mid(KeyOutput, 1, 5) & "-" & Mid(KeyOutput, 6, 5) & "-" & Mid(KeyOutput, 11, 5) & "-" & Mid(KeyOutput, 16, 5) & "-" & Mid(KeyOutput, 21, 5)
End Function