Restoring SOLIDWORKS File Associations in Windows

Article by Andrew Lidstone, CSWE updated July 25, 2011


When you double-click SOLIDWORKS files within Windows Explorer do they open up in a new, separate instance of SOLIDWORKS? If they do, then this is one of the symptoms that something is wrong with the SOLIDWORKS file associations in your Windows OS.

SOLIDWORKS files in Windows Explorer

SOLIDWORKS files in Windows Explorer

You can probably fix this by performing a repair of the SOLIDWORKS installation.

However, if this process does not resolve the behavior then the corrupted file associations will have to be manually deleted. You have two methods to choose from to delete corrupted file associations, both methods are described below:

SOLIDWORKS file associations

Set Associations

SOLIDWORKS file associations — Method 1

You can remove SOLIDWORKS file associations directly through the command prompt:

  1. Open an elevated command prompt with administrator privileges – do this by right-clicking on the Command Prompt from All Programs and execute using the ‘Run as administrator’ choice.
Run as Administrator

Run as Administrator

  1. Remove the file extension association from its assigned file type with this command:
    assoc .sldprt=

    NOTE: that after disassociation of file extension from file type, the default program for the file type will no longer been shown in the “Open With” list for the file extension.

  2. Then, clear and delete the default program used for the open command when launching files of this type with this command:
    ftype SldWorks= 

    NOTE: that if you don’t know the correct “FileType” to type, simply type assoc (associated file type will be shown after the extension) or ftype to get a listing of all file types defined in the system.

  3. Right-click on a .sldprt file, and choose the “Open With… option”, then select SOLIDWORKS from the list of installed programs to open the file, setting the correct and proper file association again.


  1. You will have to repeat the process for each SOLIDWORKS file type.

SOLIDWORKS file associations — Method 2

A standalone utility such as unassociate.exe. This was specifically created to provide this functionality, which you can use to delete the corrupted file associations.  For more information concerning the unassociated.exe utility visit this website:


NOTE this is not a SOLIDWORKS or Javelin product. Therefore Javelin cannot provide any guarantee to it’s effectiveness or safety.  As such USE IT AT YOUR OWN RISK.

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Andrew Lidstone, CSWE

Andrew is a SOLIDWORKS Elite Applications Engineer and is based in our Dartmouth, Nova Scotia office.