You can access them the same way as with XP ( disregarding the Libraries).
Go to Start > Computer > C:\ and find the Program Files folder.
You will notice that Win7 has three such folders instead of the single folder used by XP.
[ EDIT: Maybe I misread. If you can't find the download, go to C:\ Users \ Your user folder \ Downloads
for the default download directory.
If you don't find the downloaded file there then, if you use Firefox, you open the 'Downloads' Tool,
R/click and select 'Open Containing Folder' . ]
If you aren't interested in using the Libraries you can pin folders to the Windows Explorer icon
in the Taskbar. Make a shortcut for the folder and drag it from the desktop to the WE folder.
You then R/click the WE folder to open the list.
Here are a few a couple of articles that may be helpful -
Windows 7 How-To Articles, Tips, and Guides :: How-To Geek
Optimize Windows 7 for better performance
The BIG list of articles -
Win7 ABCs - Great list of Windows 7 tutorials by MVP Shawn Brink! (alphabetical)