Could not access VBScript run time for custom action

The information in this article applies to:

All versions of Nitro PDF Professional
All versions of Nitro PDF Express

Problem

When installing Nitro PDF products on Windows Vista or Windows 7, the following error is generated:

Error 2738. Could not access VBScript run time for custom action.

Cause

This error message indicates that the VBScript engine is not currently registered on the machine where the install/uninstall is taking place.

Resolution

The VBScript engine can be quickly registered by following these steps:

Run Command Prompt as administrator:
Start Menu -> All Programs -> Accessories
Right click on Command Prompt and select Run as administrator
Run the following command:
If you are using 32-bit version of Windows:
Type cd %windir%\system32 into the Command Prompt and hit Enter
If you are using 64-bit version of Windows:
Type cd %windir%\syswow64 into the Command Prompt and hit Enter
Type regsvr32 vbscript.dll into the Command Prompt and hit Enter.

If the above solution does not work, try the following alternative steps:

If you are using 32-bit version of Windows:

Run Command Prompt as administrator:
Start Menu -> All Programs -> Accessories
Right click on Command Prompt and select Run as administrator
Type the following command in the prompt: reg delete "HKCU\SOFTWARE \Classes\CLSID\{B54F3741-5B07-11CF-A4B0-00AA004A55E8}" /f, then hit Enter.
Next, you must also type the following command: c:\windows\system32\regsvr32 vbscript.dll, then hit Enter.
You should now be able to install your Nitro PDF software product.

If you are using 64-bit version of Windows:

Run Command Prompt as administrator:
Start Menu -> All Programs -> Accessories
Right click on Command Prompt and select Run as administrator
Type the following command in the prompt: reg delete "HKCU\SOFTWARE\Classes\Wow6432Node\CLSID\{B54F3741-5B07-11CF-A4B0-00AA004A55E8}" /f, then hit Enter.
Next, you must also type the following command: c:\windows\syswow64\regsvr32 vbscript.dll, then hit Enter.
You should now be able to install your Nitro PDF software product.

If the above solution does not work, try the following alternative steps:

If you are using 32-bit version of Windows:

Run Command Prompt as administrator:
Start Menu -> All Programs -> Accessories
Right click on Command Prompt and select Run as administrator
Type the following command in the prompt: reg delete "HKCU\SOFTWARE \Classes\CLSID\{B54F3741-5B07-11CF-A4B0-00AA004A55E8}" /f, then hit Enter.
Next, you must also type the following command: c:\windows\system32\regsvr32 vbscript.dll, then hit Enter.
You should now be able to install your Nitro PDF software product.

If you are using 64-bit version of Windows:

Run Command Prompt as administrator:
Start Menu -> All Programs -> Accessories
Right click on Command Prompt and select Run as administrator
Type the following command in the prompt: reg delete "HKCU\SOFTWARE\Classes\Wow6432Node\CLSID\{B54F3741-5B07-11CF-A4B0-00AA004A55E8}" /f, then hit Enter.
Next, you must also type the following command: c:\windows\syswow64\regsvr32 vbscript.dll, then hit Enter.

ref: http://kb.nitropdf.com/article.aspx?id=10106&cNode=3D8W4P