I don't know, if you will be comfortable to follow the steps or not, if not then, I can directly connect to your PC and help you to solve the problem. But, before that try to follow the steps below and reply me back.
We need to make sure a certain folder path is in your path environment variable.
Let us determine the correct path to add into the Path environment variable. Look in C:\Windows\twain_32 and there should one other folder in there. For example the folder name should be CNQ4803. This is the scanner name or number.
This is the path that is needed to be added into the path environment variable.
Now, follow these instructions to get to the dialog to modify the path environment variable.
a. Control Panel > System > and then choose Advanced System Settingsin the left hand column.
b. This will bring up the System Properties dialog (it should already be on theAdvanced tab).
c. At the bottom of this dialog is an Environment variablesbutton. Clicking this button will bring up the Environment variables dialog.
d. In the bottom panel, scroll until you find the variable named path. Select this one and then hit theEdit button to bring up the Edit System variable dialog.
e. In the Variable value text box, scroll all the way to the right and then add in the pathC:\Windows\twain_32\CNQ4803 that was determined earlier. Make sure to separate this value with a preceding semi-colon. And also be careful not to make any other changes to this value.
Now click on OK and check if it works.