Information on Perflib_Perfdata.dat Files Stored in Local Temp Folder

If you have been wondering what is Perflib_Perfdata.dat file and what is it doing in Local Settings/Temp folder, then here is the information on this file.

What was strange about Perflib_Perfdata was that this file is always there whenever you boot your computer and doesn’t get deleted.


Perflib_Perfdata is a name combined from two different words, Perflib which stands for Performance Library and the other Perfdata that means Performance Data.

You can locate these files either at C:\Windows\System32 folder or at C:\Documents and Settings\User\Local folder. The files are created by the Operating System itself and are used by system monitoring programs that is by the programs that keep an eye on the system’s performance like Disk Defrag tool.

While you can’t delete these files yourselves, they are deleted as soon as our system is shut down. However they are also formed back when we boot our computer.

P.S. If the system crashes or is not shut down properly, these files remain in the folder and then can be deleted. These are genuine Windows files and have nothing to do with the viruses.

Read More at MS

3 Replies to “Information on Perflib_Perfdata.dat Files Stored in Local Temp Folder”

  1. I do not know when I started this thread, but some malware virus create this file.
    Today is January 17, 2011, and I say that my antivirus software “Avira” detected a threat on it.
    I sent the file that was quarantined for analysis and the result was positive.
    There is a free application that removes this file. You can get it at the link below:…6a5bc34c89d005a

    I hope I have helped.

  2. This is helpful information, but, if the files are deleted at shut down and recreated at start up, it would seem to me that the only file would have the current date. I have about 11 files with older dates, some back to 2009. Is it safe to remove all those which are not the current date?

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