I can't view my downloaded files,please help!

Hello,

I have now downloaded 2 pdf files from 2 different places, one from a website and one from an email. I know they're on my desktop somewhere but I can't see them.

I have made sure that all my files and folders and not hidden (in the folder options) but they still aren't visible.

I know they are there because when I try to resave to my desktop it tells me there is already a file with that name save on the desktop and asks me if I'd like to replace it. I can also see the files when I go to attch a file to an email, but I am not able to attach the files themselves to an email.

Has anyone else come across this problem? I'm on Vista.

I would really appreciate your help,

Thank you in advance,

Karen