cannot veiw any svg files

i have a laptop with vista and desktop with xp on and for some reason i cannot view any svg files everytime i down load one (i use them for craft projects ) i get either windows cannot open this file or a load of numbers and codes far to many to attach to this post
help please in laymans terms as im not that great on computers lol

 

thank you i can view in IE but not Monzilla Firefox which is where all of my svg groups are so how do i go about that ????