使用以下功能可以访问文件的完整路径

Full path of the file can be access by using below function

string filepath = Path.getfilename (fileupload1.filename);

rgarding权限问题：

您需要为修改权限的该文件夹上的所有人组设置权限。不提供完全访问权限，但需要修改才能解决权限问题。

rgarding permission issue :
you need to set permission for everyone group on that folder with modify right. don't give full access but modify is needed to resolve the permission issue.