This is a known issue when there is no necessary patches installed on some Windows versions. The best and easiest way is to use Windows Update to update Windows. It does not only prevent PDF Driver installation problems, but your Windows will also be safer and more stable.
If you have other issues that make installing Windows patches impossible, there are two alternative solutions:
Error code 126 denotes that some modules were lost when calling Windows API function AddPrinterDriver.
Solution 1 :
A simple solution:
1. Please check if the "framedyn.dll" is usable or not in your system
2. If it is unusable, copy "framedyn.dll" from other Windows systems to corresponding system folder (Path: Windows\system32\dllcache\framedyn.dll)
3. Click "Start > All Programs > Accessories > Run" and input "%SystemRoot%\system32\wbem", click OK
4. Right-click framedyn.dll in wbem folder and choose "Properties". If file size is not 185,856, see step 5
5. Click "Start > All Programs > Accessories > Run" and input "%SystemRoot%\system32\dllcache", click OK
6. Copy framedyn.dll to wbem folder and replace the original one
Solution 2 :
1. Right-click "My Computer" in Start menu and choose "Properties"
2. Click "Environment Variables" in Advanced tag
3. Choose "Path" in "System Variables" and click "Edit"
4. Add "%SystemRoot%\System32\Wbem" to "Variable value" and click OK
5. Restart computer and reinstall Gaaiho PDF product
If the problem still exists, we recommend you to update all available patches for your Windows system.