KB00078 - The Stickies notification area icon is missing
Although Stickies starts, and creates notes on the desktop, the tray icon (next to the clock) does not appear.
Windows can hide icons it considers to be inactive. Check that there's not an arrow to the left of any icons which are there which shows the hidden ones when you click it.
If your machine is not set to hide inactive icons, but the Stickies icon is still not present, there are many reason why this might be. This is a rare problem, but in the past this link: