Powershell to install the latest Azure DevOps Agent

devops_win.ps1

param (
    [string]$URL,
    [string]$PAT,
    [string]$POOL,
    [string]$AGENT
)

Write-Host "start"

if (test-path "c:\agent")
{
    Remove-Item -Path "c:\agent" -Force -Confirm:$false -Recurse
}

new-item -ItemType Directory -Force -Path "c:\agent"
set-location "c:\agent"

[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
$wr = Invoke-WebRequest https://api.github.com/repos/Microsoft/azure-pipelines-agent/releases/latest
$tag = ($wr | ConvertFrom-Json)[0].tag_name
$tag = $tag.Substring(1)

write-host "$tag is the latest version"
$url = "https://vstsagentpackage.azureedge.net/agent/$tag/vsts-agent-win-x64-$tag.zip"

Invoke-WebRequest $url -Out agent.zip
Expand-Archive -Path agent.zip -DestinationPath $PWD
.\config.cmd --unattended --url $URL --auth pat --token $PAT --pool $POOL --agent $AGENT --acceptTeeEula --runAsService

exit 0

Thanks for the script.
If you use Azure Custom Script Extension it is necessary to use -UseBasicParsing parameter
$wr = Invoke-WebRequest -Uri "https://api.github.com/repos/Microsoft/azure-pipelines-agent/releases/latest" -UseBasicParsing

More info: https://github.com/MicrosoftDocs/azure-docs/issues/14377
https://learn.microsoft.com/en-us/azure/virtual-machines/extensions/custom-script-windows#using-invoke-webrequest