Computer newbies: Where are the installation files downloaded to??

Browser?

Firstly - what Browser are you using? In Google Chrome for example, although you can still designate WHERE you want to save the download to, there is also the automatic download to the page on Chrome "downloads" - accessible by clicking on the little spanner - top right of the Browser page. The same tool is used (under "advanced options") to select the place you want downloads to be sent to (the desktop is my favourite and I open it from there and/or send it to "My Documents" or an external memory for later use or installation on another PC). It's been so long since I used IExplorer, that I'm not too sure, but I imagine the title "Options" must be somewhere on the IExplorer page.
It's easier to ALWAYS click "SAVE" rather than "OPEN" after download, and gives you the chance to check the download with your Anti-virus programme as well as having it always available for use if needed.
Last point - unless you've got an enormous hard drive, don't forget to "empty the Browser Cache" regularly and/or empty the "temporary Internet Folders file" (you can do this very easily by running the integrated Windows "clean disk" programme under "accessories" - if you haven't got a better programme, like "CCleaner")