Download and install xmllint for Windows

xmllistInstaller.ps1

#Requires -Modules PSParseHTML
function Install-XmlLint {
    [CmdletBinding(SupportsShouldProcess)]
    param (
        [Parameter(ValueFromPipelineByPropertyName)]
        [string]
        $InstallPath = (Join-Path -Path "$env:LOCALAPPDATA\Programs" -ChildPath xmllint),
        [switch]
        $Force
    )
    
    Write-Verbose 'Starting Install-XmlLint'
    
    $baseUrl = 'http://xmlsoft.org/sources/win32'
    if ([System.Environment]::Is64BitOperatingSystem) {
        $baseUrl += '/64bit'
        $fileSuffix = '_64'
    }
    
    Write-Verbose "Base URL: $baseUrl"
    Write-Verbose "File Suffix: $fileSuffix"
    
    
    $sort += '?C=M;O=D' # Order by date, descending
    $libs = 'iconv', 'libxml2', 'libxml', 'xmlsec', 'zlib'
    $httpClient = [System.Net.Http.HttpClient]::new()
    $xmllintSite = Invoke-RestMethod -Method Get -Uri ($baseUrl + $sort) | ConvertFrom-HTML -Engine AngleSharp
    $downloadLinks = $xmllintSite.QuerySelectorAll('body > table > tbody > tr > td > a')
       
    Write-Verbose "Found $($downloadLinks.Text -match "($($libs -join '|')).*$fileSuffix") of $($libs.Count) download links"
    @'
Microsoft.Bcl.AsyncInterfaces (>= 8.0.0)
System.Buffers (>= 4.6.0)
System.Memory (>= 4.6.0)
System.Text.Encoding.CodePages (>= 8.0.0)
ZstdSharp.Port (>= 0.8.4)
SharpCompress (>= 0.1)
'@ | Select-String -Pattern '\S+(?= \(.*\))' -AllMatches | Select-Object -ExpandProperty Matches | ForEach-Object { 
 (Get-Item (Join-Path (Split-Path (Get-Package $_.Value).Source) lib/netstandard*) |
        Sort-Object { [version] ($_.Name -replace '^netstandard') })[-1] |
        Get-ChildItem -Filter *.dll -Recurse |
        ForEach-Object {
            Write-Verbose "Adding '$($_.Name)' assembly into PowerShell session"
            Add-Type -LiteralPath $_.FullName }
    }
    $extractOptions = [SharpCompress.Common.ExtractionOptions]::new()
    $extractOptions.ExtractFullPath = $true
    $extractOptions.Overwrite = $true
    
    if (Test-Path -Path $InstallPath -PathType Container) {
        Push-Location -Path $InstallPath
    }
    else {
        New-Item -Path $InstallPath -ItemType Directory | Push-Location
    }
    
    foreach ($lib in $libs) {
        $downloadLink = $downloadLinks | Where-Object -FilterScript { $_.Text -imatch "${lib}.*${fileSuffix}" } | Select-Object -First 1 -ExpandProperty PathName
        Write-Verbose -Message "Downloading '$downloadLink'"
        $downloadLink = $baseUrl + $downloadLink
    
        # Use HttpClient to download the file
        $httpClient = [System.Net.Http.HttpClient]::new()
        $response = $httpClient.GetAsync($downloadLink).Result
        $response.EnsureSuccessStatusCode() | Format-Table -AutoSize -Wrap | Out-String | Write-Debug
        $bytes = $response.Content.ReadAsByteArrayAsync().Result
        
        Write-Verbose "Downloaded $($bytes.Length) bytes"
            
        # Use SharpCompress to extract the 7z files
        $readerOptions = [SharpCompress.Readers.ReaderOptions]::new()
        $readerOptions.ArchiveEncoding = [SharpCompress.Common.ArchiveEncoding]::new()
        $readerOptions.ArchiveEncoding.Default = [System.Text.Encoding]::GetEncoding('utf-8')
    
        try {
            $sevenZipStream = [System.IO.MemoryStream]::new($bytes)
            $archive = [SharpCompress.Archives.SevenZip.SevenZipArchive]::Open($sevenZipStream, $readerOptions)
            foreach ($entry in $archive.Entries) {
                if ($entry.IsDirectory -or -not $entry.Key.StartsWith('bin/')) {
                    Write-Debug "Skipping entry: $($entry.Key)"
                    continue
                }
                Write-Verbose "Extracting entry: $($entry.Key)"
                try {
                    $entryStream = $entry.OpenEntryStream()
                }
                catch {
                    Write-Verbose "Skipping entry without a stream: $($entry.Key)"
                    continue
                }
                $outputPath = [System.IO.Path]::Combine("$env:TEMP\${lib}", $entry.Key)
                $outputDir = [System.IO.Path]::GetDirectoryName($outputPath)
                if (-not (Test-Path -Path $outputDir)) {
                    New-Item -Path $outputDir -ItemType Directory | Out-Null
                }
                $fileStream = [System.IO.File]::Create($outputPath)
                try {
                    $entryStream.CopyTo($fileStream)
                }
                finally {
                    $fileStream.Close()
                    $entryStream.Close()
                }
            }
        }
        catch {
            Write-Error -Message "Failed to open the 7z archive for '${lib}': $($_.Exception)"
        }
    
        # Copy all the files in the bin folder of each downloaded library to the xmllint folder
        Get-ChildItem -Path "$env:TEMP\${lib}\bin" | Move-Item -Destination $InstallPath -Force:$Force
        Write-Verbose "Copied files for $lib to $InstallPath"
    }
    $xmlLintExe = Get-Item -Path .\xmllint.exe
    Write-Verbose "Completed Install-XmlLint: '$($xmlLintExe.FullName)'"
    Pop-Location
}

if ($MyInvocation.InvocationName -eq '.') {
    # Install the required packages, if they're not already installed
    @'
Microsoft.Bcl.AsyncInterfaces (>= 8.0.0)
System.Buffers (>= 4.6.0)
System.Memory (>= 4.6.0)
System.Text.Encoding.CodePages (>= 8.0.0)
ZstdSharp.Port (>= 0.8.4)
SharpCompress (>= 0.1)
'@ | Select-String -Pattern '\S+(?= \(.*\))' -AllMatches | Select-Object -ExpandProperty Matches | ForEach-Object {
        $packageName = $_.Value
        if (-not(Get-Package -Name $packageName -Scope CurrentUser)) {
            Write-Verbose -Message "Installing '$packageName'" -Verbose
            Install-Package -Name $packageName -Scope CurrentUser -Source NuGet
        }
    }

    # Install xmllint into the default location
    Install-XmlLint -Force -Verbose -Confirm:$false
}

@rinilnath , I have updated the code and tested it. You can either download the cmdlet and import it as a module

<# Get xmllint installer #> (New-Object -TypeName System.Net.WebClient).DownloadString('https://gist.githubusercontent.com/mavaddat/f021e09f8c2d492e19959a9978b42544/raw/22512df43b3e11c72c2849dcae33e248a09f6cbe/xmllistInstaller.ps1') | Out-File -FilePath $env:TEMP\xmllistInstaller.ps1 -Verbose
Import-Module -FullyQualifiedName $env:TEMP\xmllistInstaller.ps1 -Verbose -Cmdlet Install-XmlLint
# Install xmllint into the default location
Install-XmlLint -Force -Verbose -Confirm:$false

Or, use the Invoke-Expression on the remote string to run the script:

<# Install xmllint #> iex (New-Object -TypeName System.Net.WebClient).DownloadString('https://gist.githubusercontent.com/mavaddat/f021e09f8c2d492e19959a9978b42544/raw/a121f0879efbb4ccb2c942605b3432531ce16cb9/xmllistInstaller.ps1')