Desktop Software that facilitates file sharing

Hi, We need a Desktop Software that facilitates file sharing. Here is how 1) The software should be invoked when a file is right clicked and 'Share' button is clicked. 2) The software should reside in the taskbar and should be invoked when double clicked. Users can either drag&drop files on the software or can right click a single file or multiple files to share it. Whichever action the user does, the software first check couple of things before uploading the file to the webserver a) File size(s) should not exceed 5mb in a single upload. b) File should either be a .jpg, .gif, .doc, .docx, .xls, .xlsx Added to this, one system can upload only a max of 100mb. Cookies should be used to prevent abuse of system. We will give a ftp storage for the files to be uploaded in. The software should upload the files into our ftp and pass this URL to the database of our website along with the date, time and email id of the user. After the insertion happens, the software should direct the user to our website from where the site will authenticate the user and map the uploaded elements to his account. During installation, the software should collect the email id of the user. This needs to be a .net application that can run in windows 2000, xp, vista and 7 operating systems. The software should also have an 'Update' functionality which can take the latest ver of the software from our website when available.