A System Restore will not restore a Start Menu shortcut.
Various ways to recreate one. Here's one:
Rightclick your start button, and choose "Explore all users" or "Explore" (depending you want the shortcut to appear in every user's Start Menu or not)
Drill down to the location you want the shortcut to appear in, rightclick an empty spot > New > Shortcut, and you're off.

Even easier, you can also simply grab the shortcut you moved with the RIGHT mouse button, and drag it to your Start Button.
After a sec, the Start Menu will pop up.
Keeping the Right mouse button depressed, drag the shortcut to the preferred location, relaease the mouse button, then choose 'copy here' from the context menu.