Installing Winget om Windows Server 2019/2022

WinGet_WinSrv.ps1

Write-Information "This script needs be run on Windows Server 2019 or 2022"

If ($PSVersionTable.PSVersion.Major -ge 7){ Write-Error "This script needs be run by version of PowerShell prior to 7.0" }

# Define environment variables
$downloadDir = "C:\WinGet"
$gitRepo = "microsoft/winget-cli"
$msiFilenamePattern = "*.msixbundle"
$licenseFilenamePattern = "*.xml"
$releasesUri = "https://api.github.com/repos/$gitRepo/releases/latest"

# Preparing working directory
New-Item -Path $downloadDir -ItemType Directory
Push-Location $downloadDir

# Downloaing artifacts
function Install-Package {
    param (
        [string]$PackageFamilyName
    )

    Write-Host "Querying latest $PackageFamilyName version and its dependencies..."
    $response = Invoke-WebRequest `
        -Uri "https://store.rg-adguard.net/api/GetFiles" `
        -Method "POST" `
        -ContentType "application/x-www-form-urlencoded" `
        -Body "type=PackageFamilyName&url=$PackageFamilyName&ring=RP&lang=en-US" -UseBasicParsing

    Write-Host "Parsing response..."
    $regex = '<td><a href=\"([^\"]*)\"[^\>]*\>([^\<]*)<\/a>'
    $packages = (Select-String $regex -InputObject $response -AllMatches).Matches.Groups

    $result = $true
    for ($i = $packages.Count - 1; $i -ge 0; $i -= 3) {
        $url = $packages[$i - 1].Value;
        $name = $packages[$i].Value;
        $extCheck = @(".appx", ".appxbundle", ".msix", ".msixbundle") | % { $x = $false } { $x = $x -or $name.EndsWith($_) } { $x }
        $archCheck = @("x64", "neutral") | % { $x = $false } { $x = $x -or $name.Contains("_$($_)_") } { $x }

        if ($extCheck -and $archCheck) {
            # Skip if package already exists on system
            $currentPackageFamilyName = (Select-String "^[^_]+" -InputObject $name).Matches.Value
            $installedVersion = (Get-AppxPackage "$currentPackageFamilyName*").Version
            $latestVersion = (Select-String "_(\d+\.\d+.\d+.\d+)_" -InputObject $name).Matches.Value
            if ($installedVersion -and ($installedVersion -ge $latestVersion)) {
                Write-Host "${currentPackageFamilyName} is already installed, skipping..." -ForegroundColor "Yellow"
                continue
            }

            try {
                Write-Host "Downloading package: $name"
                $tempPath = "$(Get-Location)\$name"
                Invoke-WebRequest -Uri $url -Method Get -OutFile $tempPath
                Add-AppxPackage -Path $tempPath
                Write-Host "Successfully installed:" $name
            } catch {
                $result = $false
            }
        }
    }

    return $result
}

Write-Host "`n"

function Install-Package-With-Retry {
    param (
        [string]$PackageFamilyName,
        [int]$RetryCount
    )

    for ($t = 0; $t -le $RetryCount; $t++) {
        Write-Host "Attempt $($t + 1) out of $RetryCount..." -ForegroundColor "Cyan"
        if (Install-Package $PackageFamilyName) {
            return $true
        }
    }

    return $false
}

$licenseDownloadUri = ((Invoke-RestMethod -Method GET -Uri $releasesUri).assets | Where-Object name -like $licenseFilenamePattern ).browser_download_url
$licenseFilename = ((Invoke-RestMethod -Method GET -Uri $releasesUri).assets | Where-Object name -like $licenseFilenamePattern ).name
$licenseJoinPath = Join-Path -Path $downloadDir -ChildPath $licenseFilename
Invoke-WebRequest -Uri $licenseDownloadUri -OutFile ( New-Item -Path $licenseJoinPath -Force )

$result = @("Microsoft.DesktopAppInstaller_8wekyb3d8bbwe") | ForEach-Object { $x = $true } { $x = $x -and (Install-Package-With-Retry $_ 3) } { $x }

$msiFilename = ((Get-ChildItem -Path $downloadDir) | Where-Object name -like $msiFilenamePattern ).name
$msiJoinPath = Join-Path -Path $downloadDir -ChildPath $msiFilename

# Installing winget
Add-ProvisionedAppPackage -Online -PackagePath $msiJoinPath -LicensePath $licenseJoinPath -Verbose

Write-Host "`n"

# Test if winget has been successfully installed
if ($result -and (Test-Path -Path "$env:LOCALAPPDATA\Microsoft\WindowsApps\winget.exe")) {
    Write-Host "Congratulations! Windows Package Manager (winget) $(winget --version) installed successfully" -ForegroundColor "Green"
} else {
    Write-Host "Oops... Failed to install Windows Package Manager (winget)" -ForegroundColor "Red"
}

# Cleanup
Push-Location $HOME
Remove-Item $downloadDir -Recurse -Force

you might want to use start-bitstransfer instead of invoke-webrequest for better performance.
i am currently working on a "side quest" to enable a customer with Windows Server 2022 and winget and so far the best automation experience for this unsupported scenario is undoubtly this project:

https://github.com/asheroto/winget-install

My summary:

# Create download directory
if (-not $(Test-Path -Path "C:\WinGet")) {
    New-Item -Path "C:" -Name "WinGet" -ItemType Directory -Force
}

# Dependencies
## Microsoft.UI.Xaml
$UIXamlPath = "C:\WinGet\Microsoft.UI.Xaml.zip"
$downloadUIXamlUri = "https://www.nuget.org/api/v2/package/Microsoft.UI.Xaml/2.8.6"
(New-Object System.Net.WebClient).DownloadFile($downloadUIXamlUri, $UIXamlPath)
Unblock-File -Path $UIXamlPath
Expand-Archive -Path $UIXamlPath -DestinationPath "C:\WinGet\Microsoft.UI.Xaml.2.8.6"
$UIXamlAppxPath = "C:\WinGet\Microsoft.UI.Xaml.2.8.6\tools\AppX\x64\Release\Microsoft.UI.Xaml.2.8.appx"
Add-AppxPackage -Path $UIXamlAppxPath

## Microsoft.VCLibs.x64.14.00.Desktop
$VCLibsPath = "C:\WinGet\Microsoft.VCLibs.x64.14.00.Desktop.appx"
$downloadVClibsUri = "https://aka.ms/Microsoft.VCLibs.x64.14.00.Desktop.appx"
(New-Object System.Net.WebClient).DownloadFile($downloadVClibsUri, $VCLibsPath)
Unblock-File -Path $VCLibsPath
Add-AppxPackage -Path $VCLibsPath

# Main Package
# Get the newest WinGet's version the download URL
$assetPattern = "*Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.msixbundle"
$releasesUri = "https://api.github.com/repos/microsoft/winget-cli/releases/latest"
$asset = (Invoke-RestMethod -Uri $releasesUri -Method Get -ErrorAction stop).assets | Where-Object name -like $assetPattern
$downloadAssetUri = $asset.browser_download_url

# Download newest version of WinGet
$installerPath = "C:\WinGet\$($asset.name)"
(New-Object System.Net.WebClient).DownloadFile($downloadAssetUri, $installerPath)
Unblock-File -Path $installerPath

# Get the newest WinGet's license file download URL
$licensePattern = "*_License1.xml"
$license = (Invoke-RestMethod -Uri $releasesUri -Method Get -ErrorAction stop).assets | Where-Object name -like $licensePattern
$downloadLicenseUri = $license.browser_download_url

# Download license file
$licensePath = "C:\WinGet\$($license.name)"
(New-Object System.Net.WebClient).DownloadFile($downloadLicenseUri, $licensePath)
Unblock-File -Path $licensePath

# Install Package
Add-AppxPackage $installerPath

# Register Package with License
Try {
    Add-AppxProvisionedPackage -Online -PackagePath $installerPath -LicensePath $licensePath -Verbose -LogPath "C:\WinGet\DesktopAppInstaller_Install.log" #-DependencyPackagePath "$UIXamlAppxPath", "$VCLibsPath"
}
Catch {
    try {
        Add-AppxPackage -Path $installerPath -DependencyPath "$UIXamlAppxPath", "$VCLibsPath" -InstallAllResources
    }
    catch {
        Write-Output $_.Exception.Message
        Write-Output $Error[0]
    }
}

# Fix Permissions (S-1-5-32-544) Local Administrators Group (Language independent)
TAKEOWN /F "C:\Program Files\WindowsApps" /R /A /D Y
ICACLS "C:\Program Files\WindowsApps" /grant "*S-1-5-32-544:(F)" /T

# Add Environment Path
$ResolveWingetPath = Resolve-Path "C:\Program Files\WindowsApps\Microsoft.DesktopAppInstaller_*_x64__8wekyb3d8bbwe"
if ($ResolveWingetPath) {
    $WingetPath = $ResolveWingetPath[-1].Path
}
$ENV:PATH += ";$WingetPath"
$SystemEnvPath = [System.Environment]::GetEnvironmentVariable('PATH', [System.EnvironmentVariableTarget]::Machine)
$SystemEnvPath += ";$WingetPath;"

not sure if all of this is really required. Can you check your approach with the one done with the linked GitHub @cquresphere