Apart from the temp files created, or used, by Internet Explorer, is it safe
to delete any other temp files?
The short answer is yes, if you can. In fact, it might even be a good thing
And it’s also “safe” to delete the temporary files used by Internet
Explorer, as long as you understand the ramifications.
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Windows Temporary Folder
In a recent article I outlined how to discover and change the location of
Windows temporary files.
Chances are if you go look at the contents of that folder, you’ll see lots
of random stuff including oddly named files and sub folders empty files and
more. In fact if you’ve never cleared out your temporary files it’s quite
possible that there’s a lot of stuff there, taking up lots of room.
And most of it doesn’t need to be there. Much of the contents of your
temporary folder is not only temporary, but stale. Unfortunately many programs
fail to clean up properly when they shut down, and any program that crashed has
no chance to clean up at all. The result is a temp folder full of “stuff”.
“Stuff” you can get rid of.
You can easily use Windows Explorer to navigate to the TMP folder (see
article to determine the location of the TMP folder on your machine). Once
there select all the files and then:
press delete to delete all the files.
If there’s no error message, you’re done.
If you get an error message indicating that a file could not be deleted
because it’s in use you have two choices after dismissing the error: either
close the program that was using it and select all files again, or select all
the remaining files except the one that is in use
Repeat until you get no errors, or the only files left are those in use
Yes, that’s cumbersome. You’ll quickly get frustrated by the number of files
in use and the number of times you might have to repeat the process.
That’s why I don’t do it that way. I use the Windows Command Shell (which
should be on All Programs, Accessories,
Command Prompt). In the command prompt, I enter two
rd /s .
Here’s what it looks like in practice:
Let’s look at each of those two commands in turn:
CD /D %TMP%
“CD” is the “Change Directory” command. (“Directory” is just another name
for “Folder”.) It says make the specified directory the current directory. “/D” means
change the current drive if necessary.” It’s safest to delete temporary files using this
technique when few, if any, programs are running.”
%TMP% is a reference to the TMP environment variable that we saw in that earlier
article. It’s a quick way to reference the temporary directory without
having to know what it is.
When the CD command has completed, you can see that the current directory
listed in the Prompt has changed to “C:\temp\sys” – that’s the temporary
directory on my machine; yours will most likely be different.
rd /s .
“RD” is the “Remove Directory” command. “/s” means “remove the specified
directory, and all subdirectories it contains, and all the files too”. So “RD
/S” means delete everything in a directory.
“.” means the current directory. So, RD then deletes the current directory
and everything in it.
Except: we don’t actually want to delete the current directory, we
really only want to delete the contents of that directory. Not to
worry: the current directory is “in use”, by us. Since it’s our current
directory it can’t be deleted. In fact, that’s what that last error message in
the example above is all about. “The process cannot access the file because it
is being used by another process.” is generated by the attempt to delete “.”,
which it cannot do.
And here’s why this approach is much easier than the Windows Explorer
approach: RD doesn’t quit if there’s an error. If it can’t delete a file or
directory it notes that in an error message, and then keeps on deleting the
rest. In fact, you can see that there is one file in use above:
“.\Perflib_Perfdata_1568.dat – The process cannot access the file because it is
being used by another process.” But all the other files and subdirectories that
were in the TMP directory are now gone.
Like I said, things tend to accumulate in the TMP folder, so I do indeed
periodically do exactly what I’ve outlined above.
Note: this technique relies on programs treating temporary files
“correctly”. By that I mean that if a program is going to rely on a temporary
file, it needs to keep it open, which prevents us from deleting it. It’s
conceivable that program could not keep the file open and get confused when the
temporary file it had just created disappeared for some reason. It’s safest to
delete temporary files using this technique when few, if any, programs are
Internet Explorer Temporary Internet Files
Nothing I’ve written about so far applies to Internet Explorer. It keeps its
temporary files in a different location entirely. In IE 7 click on the
Tools menu, Internet Options menu item, and
in the Browsing history section click on
Settings. In the resulting dialog you’ll see Current
location:, which will show you the current location of IE’s Temporary
Internet Files, also known as the “cache”.
You can certainly delete the contents of the IE’s cache; there’s a button on
the Internet Options dialog for exactly that. However your browsing experience
may slow down as IE rebuilds the cache by downloading items from the web sites
you visit frequently (items in the cache don’t need to be downloaded each time
you revisit the same page).
One warning for both.
Before you delete the contents of either your TMP folder or your Internet
Explorer cache, you’ll want to make sure you aren’t keeping important documents
in the temporary folder or cache by mistake. Typically one of the uses of
either the TMP folder or the IE cache, depending on which mail program you
might use, is to store attachments that you open. “Where did my edited attachment
go?” outlines an issue where folks can lose data by mistakenly allowing
important attachments to be saved in either of those locations.