Run command dependent on OS and IF service is present - powershell

Question

I have 2 scripts as follows that gets websites for IIS.
IIS 6 -
$website = Get-WmiObject -Class IIsWebServerSetting -Namespace "root\microsoftiisv2" | Select ServerComment | Format-Table -HideTableHeaders | out-file c:\website.txt
$b = Get-Content -Path C:\website.txt
$b | ForEach {$_.TrimEnd()} | ? {$_.trim() -ne '' } > C:\website.txt
$b = Get-Content -Path C:\website.txt
#(ForEach ($a in $b) {$a.Replace(' ', '')}) > C:\website.txt
Get-Content C:\website.txt
IIS 7+
Import-Module webadministration
$a = Get-Website | Select-Object Name
$a | ForEach-Object {
$_.name = $_.name.replace(" ","")
}
$a | Format-Table -HideTableHeaders | Out-File $DeviceDrive\Apps\NetprobeNT\Auto-monitor\Website.txt
$b = Get-Content -Path $DeviceDrive\Apps\NetprobeNT\Auto-monitor\Website.txt
$b | ForEach {$_.TrimEnd()} | ? {$_.trim() -ne '' } > $DeviceDrive\Apps\NetprobeNT\Auto-monitor\Website.txt
$b = Get-Content -Path $DeviceDrive\Apps\NetprobeNT\Auto-monitor\Website.txt
#(ForEach ($a in $b) {$a.Replace(' ', '')}) > $DeviceDrive\Apps\NetprobeNT\Auto-monitor\Website.txt
I have a different script for IIS 6 (Windows 2003 hosts) because webadministration module is not available for II6.
I need to add an if statement that will add logic to run the correct code dependent on the host operating system and if W3SVC service (World Wide Web Publishing Service) is present (running or stopped). Something along the lines
IF W3SVC is present
Check host operating system
IF operating system = Windows 2003
Run II6 code
Else
Run II7+ code
I don't know where to begin with this script. PowerShell and scripting is new to me and this is part of my first script I am creating. Any help will be greatly appreciated.
I can get the host operating system but confused on how I would put logic into it to get the results I need.
(Get-WmiObject Win32_OperatingSystem).Name

Answer 1

Use Caption rather than Name. Other than that you simply plug the routine into your pseudocode:
if ((Get-WmiObject Win32_OperatingSystem).Caption -eq 'Windows 2003') {
# Run II6 code
} else {
# Run II7+ code
}
For the service you can use the Get-Service cmdlet:
if (Get-Service -Name w3svc -ErrorAction SilentlyContinue) {
...
}
or Get-WmiObject on the Win32_Service class if the Get-Service cmdlet isn't available in PowerShell v2 (not sure about that):
if (Get-WmiObject Win32_Service -Filter "Name='w3svc'") {
...
}