Cannot upload attachments

Try with some other browser,or try with some other attachment so that when you change the attachment it may work ,Try attaching through yahoo if gmail is not working.Try hotmail try and try ,then see the tools of the browser ,internet options check everything till you succeed.http://en.wikipedia.org/wiki/Email_attachment

First thing i want know if your internet connection is slow or not. If there is slow connection then might be problem in uploading which lead because of connection fault. I had faced this problem too much as i had slow connection. If you have good connection speed for internet then i dodn't think this problem will be there. If there is then try to removes cookies and clear history and caches and re login to your gmail and then try one. I think it will work.