powershell error when key is not present - powershell

Question

i have made my script
$officeversion = reg query "HKEY_CLASSES_ROOT\Outlook.Application\CurVer"
if ($officeversion -eq " (Default) REG_SZ Outlook.Application.16"){
Write-Host "Office 2016"
Exit 0
}
if ($officeversion -eq " (Default) REG_SZ Outlook.Application.15"){
Write-Host "Office 2013"
Exit 0
}
if ($officeversion -eq " (Default) REG_SZ Outlook.Application.14"){
Write-Host "Office 2010"
Exit 0
}
if ($officeversion -eq " (Default) REG_SZ Outlook.Application.12"){
Write-Host "WARNING: Office 2007"
Exit 1010
}
if ($officeversion -eq " (Default) REG_SZ Outlook.Application.11"){
Write-Host "ALERT: Office 2003"
Exit 1010
}
if ($officeversion -eq " (Default) REG_SZ Outlook.Application.10"){
Write-Host "ALERT: Office XP"
Exit 1010
}
else {
Write-Host "No Office Installed"
Exit 0
}
but when they key is not present, im getting the following error:
reg : ERROR: The system was unable to find the specified registry key or value.
At C:\Users\syslocal\Desktop\RepopulateTDL2.ps1:1 char:18
+ ... iceversion = reg query "HKEY_CLASSES_ROOT\Outlook.Application\CurVer"
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (ERROR: The syst...y key or value.:String) [], RemoteException
+ FullyQualifiedErrorId : NativeCommandError
does anyone have a suggestion that I can suppress this error if the key doesn't exist?
Thank You

Answer 1

You can use PowerShells Registry provider to access the registry.
New-PSDrive -PSProvider Registry -Root HKEY_CLASSES_ROOT -Name HKCR
Then you can use commands like Get-Item, Get-ChildItem and Test-Path like you would on regular files and directories. That way you can use PowerShells error handling like the -ErrorAction parameter or try / catch blocks and all the good stuff.
Get-Item HKCR:\Outlook.Application\CurVer -ErrorAction Ignore
On a side note: for your script above, you should look into the switch statement, instead of using many if statements.

Answer 2

As others will no doubt point out, and you may already even be aware, using CMD commands in PowerShell is not the way PowerShell was meant to be used. It is more than capable of running registry queries with its own toolset. The main reason you want to stick to PowerShell cmdlets whenever possible is so that you don't have to worry about situations like this, where the program returns the error to the same stream as the successful output and you as a coder have to account for it. The advantage of PowerShell cmdlets is that different outputs are sent to different streams. See Guide. I would suggest moving to something like this if at all possible:
Get-ChildItem -Path "Registry::HKEY_CLASSES_ROOT\Outlook.Application\CurVer"
As I do understand that there are occasions where best practice is not possible, the solution you want to look to is called Try {} Catch {}. Now I'm not able to recreate your error message but I have gotten as close as I can. See example:
Try {
$officeversion = reg query "HKEY_CLASSES_ROOT\Outlook.Application\CurVer"
}
Catch [System.Management.Automation.ItemNotFoundException] {
# Registry path was not found
}
Catch {
# Some other error was thrown
}
Finally {
# Cleanup actions
# This step happens regardless of whether or not an error was thrown
}
See here for good documentation about Try {} Catch {}

Answer 3

Redirect stderr to $null
$officeversion = reg query "HKEY_CLASSES_ROOT\Outlook.Application\CurVer" 2> $null

Answer 4

this kinda works,
thanks for directing me in the correct directions i end up with
$officeversion = (get-itemproperty -ErrorAction Ignore -literalpath HKCR:\Outlook.Application\CurVer).'(default)'
if ($officeversion -eq "Outlook.Application.16"){
Write-Host "Office 2016"
Exit 0
}
if ($officeversion -eq "Outlook.Application.15"){
Write-Host "Office 2013"
Exit 0
}
if ($officeversion -eq "Outlook.Application.14"){
Write-Host "Office 2010"
Exit 0
}
if ($officeversion -eq "Outlook.Application.12"){
Write-Host "WARNING: Office 2007"
Exit 1010
}
if ($officeversion -eq "Outlook.Application.11"){
Write-Host "ALERT: Office 2003"
Exit 1010
}
if ($officeversion -eq "Outlook.Application.10"){
Write-Host "ALERT: Office XP"
Exit 1010
}
if ($officeversion -eq "Outlook.Application.10"){
Write-Host "ALERT: Office XP"
Exit 1010
}
else {
Write-Host "No Office Installed"
Exit 0
}
i will still look to the switch statement later

Answer 5

you could test if key is present or not with
Test-path "HKLM:\software\classes\outlook.application\curver"
you ll have statement to $true or false