[X-SW] HELP, please.

[Rupert Hoyte]

Many attachments to emails, these days,  come as a large rectangle in which is a small blue square and question mark.   I find that my Mac will open about half of these,  but with a number of them it can do nothing.  Now i think all the function mechanisms of my computer, (Snow Leopard)  are right up to date, as I always download these when offered.   Is there something I can do (download ?) to enable all such attachments to be opened. ?  Thank you.

IN your reply, if there are instructions,  please state each step clearly,  don't take it for granted I am a computer whiz.   Thanks.