Here are step-by-step instructions to delete a user's temporary files using PowerShell commands. I will also show you how to script environmental variables, such as Temp or windir.
Please Note: Unusually for me, I have been unduly
cautious on this page, because if a delete script goes wrong it could be
devastating.
Our mission is to create a PowerShell script which deletes all files in a user's temp folder. The point of this exercise is to free up disk space and
possibly speed up a machine's performance. What the script does is remove files left behind by programs that are unable to clear up after they close. My idea would be to run this script just after
machine startup or just before shutdown.
In XP most, but not all, temp
files are stored in the folder which corresponds to: %USERPROFILE%\Local Settings\Temp or in Vista: %USERPROFILE%\AppData\Local\Temp
The key point is that %temp% environmental variable
controls the location of this Temp folder in all Microsoft Operating systems. To cut a long story short, script this variable in PowerShell by employing: $env:temp.
Trap I do not like disclaimers.
However, let me say two things: Firstly, take extra care with ANY script which deletes data. Secondly, abandon the usual method of mindlessly copying and pasting the code, and instead, take the time
to understand each component.
Addendum
Jo Enright wrote in saying that a program that he was trying to install would not work. The reason was that it needed temp files after the reboot. Sadly, the PowerShell script deleted those temp
files.
Windows Management Instrumentation (WMI) is one of the hidden
treasures of Microsoft operating systems. Fortunately, Solarwinds
have created a
Free WMI Monitor so that you can discover these gems of performance
information, and thus improve your PowerShell scripts. Take the guess work out of which WMI counters to use when scripting the
operating system, Active Directory or Exchange Server.
To make sense of this script you must understand Environmental Variables. Here is how
to check
your operating system's temp and windir variables: Press: Windows Key +r (Run dialog box appears): Type: %temp%. You can also try: Start, Run, %windir%.
What I would like to do next is
make the connection between what happens when you 'Run' these %variables%, with what you see in this location: System Icon, Advanced, Environmental
Variables. Note in passing that Temp and Tmp occur under both the User and System variables. Also be aware that the User's %temp%, which we will use in our script, corresponds to %USERPROFILE%\Local
Settings\Temp. As you may already know, in XP the %USERPROFILE% is stored under the Documents and Settings folder.
To gain confidence, and for the sake of safety, I want start by
just listing the temporary files.
Instructions
Method 1 - Copy and paste the code below into a PowerShell command box. Left-click on the PowerShell symbol (Top Right of box),
select Edit, Paste and then press Enter twice.
Method 2 (Better) - Copy the code below into a text file and thus create a cmdlet. Save with .ps1 extension e.g. C: \scripts\List.ps1.
Navigate in PowerShell to
C:\scripts. Type dir, you should see a file called list.ps1 (Type) .\list [Dot backslash filename]
# PowerShell Temp File Script to List the Temp Files $GuyTemp = "$Env:temp" set-location $GuyTemp $Dir = Get-Childitem $GuyTemp -recurse $List = $Dir | Where-object {$_.extension -eq ".tmp"} foreach ($_ in $List ){$_.name $count = $count
+1} "Number of files " +$count
Note 1: It is hard to believe, but the most difficult part of this project was researching the correct syntax for : $Env:temp.
Note 2: Set-location is
much like CD (Change Directory)
Note 3: Get-Childitem, with used with the
-recurse parameter, is like the dos /s switch.
Note 4: Where-object is just a safety clause to make sure that we
only list .tmp files.
Note 5: The key to PowerShell's loop syntax is to examine the two types of bracket (condition) {Do Stuff}
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Here is extra code, which outputs the list to a file. The key point is to pipe (|) the result to out-file.
# Powershell Temp Files List --> Output to a File # Warning C:\ is a silly destination # Better edit to: "C:\scripts\ListTemp.txt" $File = "C:\ListTemp.txt" $GuyTemp = "$Env:temp" set-location $GuyTemp $Dir = Get-Childitem $GuyTemp
-recurse $List = $Dir | Where-object {$_.extension -eq ".tmp"} foreach ($_ in $List ){$Temp = $Temp + "`t" + $_.name $count = $count +1} "Number of files " +$count $Temp | out-file -filepath
$File
Note 1: I hope that you changed this line: $File = "C:\ListTemp.txt". It is bad practice to save such files to the root; however, my problem is that I do not know if you have a
c:\scripts folder, so I dare not save to a non-existent folder.
Note 2: `t is PowerShell's tab command; the equivalent of VbTab.
As John McEnroe
would say, 'You cannot be serious'. How could the tiny script below have the ability to find, and then delete all the temporary files? Part of the answer is: 'PowerShell punches above
its weight; every word is loaded with meaning. The other answer is more mundane, the script does not delete ALL the temporary files because some are in use!
Instructions
Method 1
- Copy and paste the code below into a PowerShell command box. Left-click on the PowerShell symbol (Top Right of box), select Edit, Paste and then press Enter twice.
While this script has more code than Example 3a, it is no better. However, it has the interesting feature that it displays the number of
temporary files. When I ran Example 1 (Listing) I had 256 tmp files. Once I ran Example 3b, I only had 12 tmp files, and they are in needed by programs running on my machine. Thus the
Remove-Item command is working.
With PowerShell a little code goes along way. Here on this page is a potent script, which is useful for deleting a user's temporary files.
Summary of PowerShell Temp Files Deletion
As usual, I like to split a PowerShell task into chunks. My strategy is to master each chunk of code, then bolt together all the components, thus creating the
final script. In the case of PowerShell, these chunks are exceedingly small. The part that took me the longest was to master the special environmental variable: $env:Temp. Fretting about just these 9 characters
looks silly now, but it does emphasise the efficiency of writing code in PowerShell.
Remove-Item was another chunk of code that I experimented with in its own test-bed. I am still nervous that you could
mis-read or mis-apply this command, and consequently delete all of your Windows files. Consequently, do be careful, think about what you are doing and make sure that you understand the implications of the
-recurse and -force switches.
If you like this page then please share it with your friends
See More Windows PowerShell Examples of Real-life Tasks
Please email me if you have a better example script. Also please report any factual mistakes, grammatical errors or broken links, I will be happy to correct the fault.
Windows Management Instrumentation (WMI) is one of the hidden
treasures of Microsoft operating systems.
Fortunately, Solarwinds
have created the
Free WMI Monitor so that you can actually see and understand these gems of
performance information. Take the guess work out of which
WMI counters to use for applications like Microsoft Active Directory,
SQL or Exchange Server.
