To correct the problem you can use the clean install steps for the 3Dconnexion software at
http://www.3dconnexion.com/faq/28 . The path listed for Vista is also correct for Windows 7.
If the Clean install does not add the 3DsMax plug-in, there are manual steps you can use:
On a 32-bit PC:
Copy the "3dxstd.dlu" file from C:-->Program Files-->3Dconnexion-->3Dconnexion 3DxSoftware-->3DxStudio32-->win32 -->3DsMax2012 to the "stdplugs" sub-directory of 3Ds Max.
Copy "3DxStudio.ms" from C:-->Program Files-->3Dconnexion-->3Dconnexion 3DxSoftware-->3DxStudio32 to the scriptsstartup sub-directory of 3Ds Max.
On a 64-bit PC:
Copy the "3dxstd.dlu" file from C:-->Program Files-->3Dconnexion-->3Dconnexion 3DxSoftware-->3DxStudio64-->x64 -->3DsMax2012 to the "stdplugs" sub-directory of 3Ds Max.
Copy "3DxStudio.ms" from C:-->Program Files-->3Dconnexion-->3Dconnexion 3DxSoftware-->3DxStudio64 to the scriptsstartup sub-directory of 3Ds Max.
The manual has a screenshot of the 3DsMax Pop-Up Menu. [Start, Programs,3Dconnexion,Documentation - Manuals
- English Manual - Supported Applications - Autodesk 3ds Max]
===============================================[Note: 3dsMax versions 9 through 2012 all use 3dxstd.dlu but the files are different and have a different file size
based on the year and version]
3DsMax9 : 2.06 MB
3DsMax2008 : 2.06 MB
3DsMax2009 : 2.07 MB
3DsMax2010 : 2.18 MB
3DsMax2011 : 2.18 MB
3DsMax2012 : 2.07 MB