C:\Users\All Users\Start Menu. There's another copy in C:\Users\yourid\AppData\Roaming\Microsoft\Windows\Start Menu. However it's going to be hard to modify it there due to access protection. What you CAN do is to click Start and then right-click All Programs and then click Open. This opens a new window with the Start Menu where you can make additions. Personally I prefer to put shortcuts on the desktop, but you can do it either way.
So, finally upgraded from XP to 7. One question; in XP, through Windows Explorer, I was able to create individual folders in the Programs menu of Start Up for linked Programs i.e. Web Browsers, Utilities, Photo Editing etc. This avoided scrolling through a long list of programs. I'm not finding the Start Up/Programs menu in Windows Explorer on Windows 7. Any suggestions? Thanks in advance.