Email attachments - Windows logo only

[Johnno]

Hi, i recently installed a trila version of Nero 7 and upon expiry, removed it as a program. Now, i can not open any email attachements, especially pictures. The microsoft windows flag appears in the attachment, whereas before it may have been a jpeg, etc. Can any one advise me how i should reinstate the ability for my computer to determine what program it should be using to open an attcahment? What have i done!!? Kind regards Johnno