Hi, 

I have successfully installed regsvr32 mscomct2.ocx on my Windows 8.1 machine Excel 2013, 32 bit, Office 365. I can access the Microsoft Slider control 6.0 but when i try to drop it on either the user form or the worksheet, there is an error message - Cannot insert object.

Could you please help? 

Hi,

According to your description, this error message may be caused by the MS14-082 Microsoft Office Security Updates for December 2014.

To workaround this issue, we must delete the cached versions of the control type libraries (extender files) on the client computer. To do this, perform a search on your hard disk for files that have the ".exd" file name extension and delete all the .exd files that you find. These .exd files will be re-created automatically when you use the new controls the next time that you use VBA. These extender files will be under the user's profile and may also be in other locations, such as the following: 

• %appdata%\microsoft\forms
• %temp%\excel8.0
• %temp%\word8.0
• %temp%\PPT11.0
• %temp%\vbe

Quote From:

http://blogs.technet.com/b/the_microsoft_excel_support_team_blog/archive/2014/12/13/forms-controls-stop-working-after-december-2014-updates-.aspx

Regards,

George Zhao
TechNet Community Support