Using get -childitem to scan different drives but append one text file.

Folks,

I need some help, I wrote the below to scan for certain files types on client machines but I cant get the script to scan anything other than the C$. Apologies I am kind of new to scripting and PS. The script is kicked off using a batch file that makes the CR directory on the clients. I think the problem stems from the $disk variable or the way I have used foreach or the loop - any help would be appreciated

Set-Location c:\
$s = new-object -comObject SAPI.SPVoice
$s.speak("Scan in progress")
write-host "Scanning for files"
$Extension = @("*.zip","*.rar","*.ppt","*.pdf")
$Path = "$env:userprofile\Desktop"
$disks = "c$","D$"
foreach ($disks in $disks)
{get-childitem -force -include $Extension -recurs -EA SilentlyContinue >$path\files.txt}
$s.speak("Scan completed")
Write-Host "Scan complete, files.txt created on your desktop - press any key to exit..."
$x = $Host.UI.RawUI.ReadKey("NoEcho,IncludeKeyUp")
Remove-Item c:\cr -recurse -EA SilentlyContinue
exit