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.