Create a Powershell variable

Question

Create a Powershell variable

George Sinkinson 110

In Powershell, I'm trying to set up the $outputPath variable like:

$outputPath = "C:\directory\computer name_date.reg"

where

directory is hardcoded (C:\Temp)

computer name is the computer name from the system (GSINKINSON)

date is in yyyymmdd format from the system (20251222)

so it would look like

$outputPath = "C:\Temp\GSINKINSON_20251222.reg"

To be used with the script below run as administrator:

Define the output file path.

$outputPath = ""C:\directory\computer name_date.reg""

Write-Host "Exporting registry."

The command below uses regedit.exe to export the full registry.

It requires administrative privileges.

Start-Process -FilePath "regedit.exe" -ArgumentList "/E", ""$outputPath"" -Wait -NoNewWindow

Write-Host "Registry export complete."

This is pretty much my first attempt at Powershell scripting ...

George Sinkinson 110 Reputation points

2025-12-23T00:00:54.0733333+00:00

Not sure where the Bold, larger Font came from ...
S.Sengupta 27,611 Reputation points MVP

2025-12-23T02:17:53.6933333+00:00

In PowerShell you just need to build the filename from system variables and format the date, then pass it correctly to regedit.exe.

$env:COMPUTERNAME

Get-Date -Format "yyyyMMdd"

1 answer

Your answer

George Sinkinson 110 Reputation points

2025-12-23T00:00:54.0733333+00:00

Not sure where the Bold, larger Font came from ...
S.Sengupta 27,611 Reputation points MVP

2025-12-23T02:17:53.6933333+00:00

In PowerShell you just need to build the filename from system variables and format the date, then pass it correctly to regedit.exe.

$env:COMPUTERNAME

Get-Date -Format "yyyyMMdd"

Answer 1

Marcin Policht 70,050 MVP Volunteer Moderator

You can dynamically build $outputPath in PowerShell by combining a hardcoded directory, the system’s computer name, and the current date in the format you want. You don’t need extra quotes inside the string unless you are trying to escape something, PowerShell handles variable expansion inside double quotes. For your example, it would look like this:

$directory = "C:\Temp"
$computerName = $env:COMPUTERNAME
$date = Get-Date -Format "yyyyMMdd"
$outputPath = "$directory\$computerName`_$date.reg"

Here, $env:COMPUTERNAME retrieves the computer name from the system, Get-Date -Format "yyyyMMdd" gives the date in the format 20251222, and the backtick before _ is optional but can prevent ambiguity if needed. This will produce something like C:\Temp\GSINKINSON_20251222.reg.

Then your export part can use $outputPath directly:

Write-Host "Exporting registry."
Start-Process -FilePath "regedit.exe" -ArgumentList "/E", "$outputPath" -Wait -NoNewWindow
Write-Host "Registry export complete."

This avoids double quotes inside quotes, which can confuse PowerShell, and ensures the path is built dynamically for any system and date.

If the above response helps answer your question, remember to "Accept Answer" so that others in the community facing similar issues can easily find the solution. Your contribution is highly appreciated.

hth

Marcin

George Sinkinson 110 Reputation points

2025-12-24T03:17:53.6666667+00:00

Works beautifully - thank you very much.

My script now looks like this:

Get the directory name

$directory = "C:\Temp"

Get the computer name

$computerName = $env:COMPUTERNAME

Get the current date in yyyymmdd format

$date = Get-Date -Format "yyyyMMdd"

Define the output file path

$outputPath = "$directory$computerName`_$date.reg"

Write-Host "Exporting registry."

The command below uses regedit.exe to export the full registry.

It requires administrative privileges.

Start-Process -FilePath "regedit.exe" -ArgumentList "/E", "$outputPath" -Wait -NoNewWindow

Write-Host "Registry export complete."

Do you have a suggestion as to where to find a good site to learn how to code in Powershell properly?

I ask because if I copy the above lines into the Powershell Administrator window,
it works.

But if I save the code in Test.ps1, right-click on the file and select run as administrator, I get an error about the file not having an app associated with it.

I haven't been able to find a way to accomplish that.
Marcin Policht 70,050 Reputation points MVP Volunteer Moderator

2025-12-24T04:25:18.02+00:00
What’s tripping you up first is that the lines like “Get the directory name” are not comments. In the interactive console they’re ignored because you probably didn’t paste them, but in a .ps1 file PowerShell tries to execute them as commands and that will break the script. In a script file, comments must start with #. Also, you’re missing the backslash between the directory and the computer name. Your script should look like this:

# Get the directory name $directory = "C:\Temp" # Get the computer name $computerName = $env:COMPUTERNAME # Get the current date in yyyymmdd format $date = Get-Date -Format "yyyyMMdd" # Define the output file path $outputPath = "$directory\$computerName`_$date.reg" Write-Host "Exporting registry." # Export the full registry (requires admin) Start-Process -FilePath "regedit.exe" -ArgumentList "/E", "$outputPath" -Wait -NoNewWindow Write-Host "Registry export complete."

Now, about the “no app associated with it” error when you right-click the .ps1 file: by default, Windows does not associate .ps1 files with PowerShell for double-click or right-click execution for security reasons. That’s normal behavior.

The usual way to run a script as administrator is:

Open Start, type PowerShell, right-click “Windows PowerShell” or “PowerShell 7”, choose Run as administrator, then run:

cd "C:\Path\To\Your\Script" .\Test.ps1

If you also get an error about scripts being disabled, set the execution policy once (as admin):

Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope LocalMachine

Then answer Y.

If you really want a right-click option, you can use “Run with PowerShell” from the context menu, but even that won’t automatically elevate to admin. Elevation almost always needs to be done by launching PowerShell itself as administrator.

As for learning PowerShell properly, some very good starting points are Microsoft Learn’s PowerShell learning paths and the PowerShell documentation at learn.microsoft.com under “PowerShell”. Also, running Get-Help about_* and Get-Help <cmdlet> -Full inside PowerShell is helpful for understanding how things work.

If the above response helps answer your question, remember to "Accept Answer" so that others in the community facing similar issues can easily find the solution. Your contribution is highly appreciated.

hth

Marcin

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Create a Powershell variable

Define the output file path.

The command below uses regedit.exe to export the full registry.

It requires administrative privileges.

1 answer

Get the directory name

Get the computer name

Get the current date in yyyymmdd format

Define the output file path

The command below uses regedit.exe to export the full registry.

It requires administrative privileges.

Your answer