Download problems

A week ago my Home Vista suddenly started failing to download attachments from emails or for example videos from Internet. The download process seems to work normally, but when it's complete the download is nowhere to be found, nor am I able to doubleclick on the download window and open the file. Any thoughts ?

OK, problem solved. Noticed my AVG package was signalling the email scanner wasn't working ( goodness knows why ). Re-installed and everything's tickety-boo again.