Since moving from Windows XP to Windows 8.1 have been unable to send attachments or scanned items by btinternet.com , I get the reply that '' this email needs to be associated with a program that will enable this''. I use Firefox as a browser and my email program is contained as a tab within Firefox exactly as it was in Windows XP where it all functioned perfectly. Any help appreciated.
Are you using BTYahoo or BTMail. If you are not sure check by using this link
http://diagnostics.bt.com/login/?workflow=EmailChecker
What happens if you log on using this link
https://signin1.bt.com/login/emailloginform
What version of Firefox are you using?
You should also have a look at these threads. They might help.
https://community.bt.com/t5/Email/How-to-attach-files-in-the-new-BT-Yahoo-system/td-p/1483429