You will be able to use WinScan2PDF both from your hard drive as well as from a USB pendrive, because it is portable and it doesn't require installation. Once launched, you only have to select the source. WinScan2PDF will detect the scanner that you have installed automatically. When you click on the Scan to PDF button, WinScan2PDF will perform the scan and will allow you to save it in PDF format.
WindScan2PDF also has a multipage function, with which you will be able to create a document with as many pages as elements that you scan.
This is how simple and useful WinScan2PDF is. For those people that scan documents to send them by email and need them to be in PDF format, WindScan2PDF is the ideal tool.