When I attempt to download something, such as adobe 10, on my Vista, a window appears saying that there is no application to open it. It says that for every download I try... What do I do?

Is this a new computer? If so maybe what you are trying to download is in .RAR file and your computer doesn't know what to do with it. When you get the popup saying nothing to open with there should be a line on there to search the internet for a program. Use that feature and check the recommended list.

Firstly, you should virus check all downloaded files before you try to open them. You may want to change your windows settings to include file extensions, as well as the file names. Once you know what type of file you are dealing with, it will be easier for you to find out how to open it. Google 'how do I open files with extension .mp3' for example. Or include