Hi,
You may want to try the following...
1, Open
Control Panel > Network and Internet > Internet Options
2, Click the
Advanced tab then
Restore Advanced Settings followed by
Reset
3, Click
Start > Default Programs then
Set program access and computer defaults
4, Click the arrow dropdown on the right of the
Current Default (normally 'Custom') selection and select
Email Preferences

Note
Make sure that Allow Access is check for whatever program you are setting at the default
Hope this helps
OS