# Script to change all registry entries containing old username to new username.
#
# 1. Create a second admin account on your PC
# 2. Log out of your primary account and into the secondary account
# 3. Rename profile via Control Panel > User Accounts
# 4. Rename old username in C:\Users\ to new username
# 5. Change the two variables below and run the script in Admin PowerShell. It will take a long time.
# 6. Log into the renamed profile and run the script again. This will change the registry entries that may be only editable by the owner account.

# Define the old and new user paths
$oldUserPath = "\Users\Jeremy" 
$newUserPath = "\Users\MisterAnonymous"

#################################################################################################################################################

# Function to search and replace in registry key values
function Replace-RegistryValue {
    param (
        [string]$rootKeyPath
    )
    
    # Get all registry subkeys recursively
    $subKeys = Get-ChildItem -Path $rootKeyPath -Recurse -ErrorAction SilentlyContinue

    foreach ($subKey in $subKeys) {
        # Get all properties (values) under each key
        $properties = Get-ItemProperty -Path $subKey.PSPath -ErrorAction SilentlyContinue

        foreach ($property in $properties.PSObject.Properties) {
            # Check if the value contains the old user path
            $oldValue = $property.Value
            if ($oldValue -like "*$oldUserPath*") {
                $newValue = $property.Value -replace [regex]::Escape($oldUserPath), $newUserPath
                Set-ItemProperty -Path $subKey.PSPath -Name $property.Name -Value $newValue
                Write-Host "Updated: $($subKey.PSPath)\$($property.Name)`nFrom $oldValue to $newValue"
            }
        }
    }
}

# List of registry root keys to search (can be extended based on the need)
$registryRoots = @(
    "HKCU:\",
    "HKLM:\",
    "HKCR:\",
    "HKU:\",
    "HKCC:\"
)

# Loop through each root key and apply the search/replace function
foreach ($rootKey in $registryRoots) {
    Write-Host "Searching in $rootKey..."
    Replace-RegistryValue -rootKeyPath $rootKey
}

Write-Host "Registry update completed."