Outlook will not allow me to insert attachments in my email.  Whenever I try to load an attachment I get the following error message:

 

iexplore.exe - Application error

The instruction at 0x68fb75f7 referenced memory at 0X0000000 could not be read

Outlook was working fine yesterday, today it is saying page not found check I have used right address!!! Have been trying all morning to access my email without luck!! All other sites are ok so it is not internet access. Could do with some help here as I am awaiting important emails. The actual message says

FIREFOX CAN'T FIND PAGE dub101.mail.live.com PLEASE CHECK THE ADDRESS????

Thank you