This will generate an html table that lists available COM ports on windows. It can be styled with css.

AvailableComPorts.ps1

# Multi-Line
$style = @"
<style type="text/css">
th {
    background: lightblue
}
tr {
    text-align:left
}
table, th, td{
    border: 1px solid black;
}
</style>
"@ 

Get-WMIObject Win32_SerialPort | `
Select-Object DeviceID,Name,Description | `
Sort-Object DeviceID | `
ConvertTo-HTML -Head $style

# One Line
Get-WMIObject Win32_SerialPort | Select-Object DeviceID,Name,Description | Sort-Object DeviceID | ConvertTo-HTML -Head $style