Fix for Error 100 Invalid Class String in Internet Explorer When Opening Organize Favorites


When you click the Organize Favorites option under the Favorites menu in Internet Explorer, the following error occurs and the Organize Favorites dialog appears blank as in the graphic below:

An error has occurred in this dialog.

Invalid class string

This happens due to missing Microsoft JScript registration. And the fix is to register the DLL.

Windows XP

1. Login to an account that has administrative privileges.

2. Click Start, Run. Type the following command:

regsvr32 jscript.dll

3. Press {ENTER}

Windows Vista and Windows 7

1. Open an elevated Command Prompt window. To do so, click Start, click All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator.

2. Type the following command:

regsvr32 jscript.dll

3. Press {ENTER}

You should see the "DllRegisterServer in jscript.dll succeeded." message box.

Logoff and login back. See if you’re able to open the "Organize Favorites" dialog in Internet Explorer successfully.


About the author

Ramesh Srinivasan founded back in 2005. He is passionate about Microsoft technologies and has a vast experience in the ITeS industry — delivering support for Microsoft's consumer products. He has been a Microsoft MVP [2003 to 2012] who contributes to various Windows support forums.

15 thoughts on “Fix for Error 100 Invalid Class String in Internet Explorer When Opening Organize Favorites”

  1. I am still using Windows XP and had the same problem as a nonprivileged user, not as administrator, but the hint didn’t fix the problem.

  2. Thanks. This fixed issue I’ve been having with e-bank on website opened through “favorites”.

  3. It fixed the favorites problem and also fixed the problem of micosoft update not being able to change to windows update.

  4. Very helpful, and it worked. I’m surprised that this solution wasn’t offered by
    Microsoft’s own support team on their own support forums!

  5. Thanks so much. The problem I was having was with MMC (Microsoft Management Console). After a long circuitous route to track down where the problem was on my system I happened to find that Organize Favorites was also not working properly, I ended up here, and it solved the MMC problem.

  6. Excellent! After months working with problems in my IE, this command line has fixed “JUST” everything! Thanks a lot!

  7. I was in need of help on this, and the fix described here worked just fine.
    The other fixes I came across seemed to involve Regedit and deleting the existing Favorites, which I couldn’t believe was necessary. Overkill.
    Nice work.

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