PowUpload supports PUT method defined in W3C RFC 2616 that is specialy designed to upload files.
PUT method allows resumable upload which PowUpload also supports. The main problem is that most browsers don't supports PUT method. Users should use external ActiveX or Java applets which supports PUT method.
One of them is JUpload. It is third party software and you need to buy license for this product separatly.

Before using this sample make following steps:
1. Download last JUpload release from official website and copy at least dist\ folder to the root of application!
2. Open application properties at IIS, Under "Directory" tab click "Configuration..." button. Select ".aspx" extensions in the list and click "Edit..." button. Add PUT verbs support i.e select "All verbs" or limited to "GET,HEAD,POST,DEBUG,PUT"

Select large files to upload, click "Stop upload" and then "Upload files" while uploading to test resumable upload.
Your browser does not support Java Applets or you disabled Java Applets in your browser-options. To use this applet, please install the newest version of Sun's Java Runtime Environment (JRE). You can get it from java.com
Newest version of Sun's Java Runtime Environment (JRE) available at www.java.com

JUpload control Official Website

The official JUpload project website, Documentation and Last Release can be found at this place: www.jupload.biz
Other examples       View C Sharp source code   View VB NET source code

Used files: Bin\Element-IT.PowUpload.dll, Web.Config, JUpload files, JUpload.aspx, JUploadProcess.aspx, Styles.css [Optional]