I used to notice the Safely Remove Hardware icon was always missing from my taskbar. It was pretty weird. I would log in as Admin to my Windows XP PC but the Safely Remove Hardware Icon would always be missing. So I surf around and found 2 solutions.
1. Run a command to bring up the Safely Remove Hardware dialog screen.
There are times that the Safely Remove Hardware Icon is missing or disappeared from the try bar. In Windows Safe Mode, you can’t find the Safely Remove Hardware icon at all! Is shutting down the computer the only way to safely stop and unplug your USB devices? Fortunately not. Here are some ways you can bring back the Safely Remove Hardware window when the icon is missing. source
2. Download an app called USB Disk Ejector. A program that allows you to quickly remove USB devices in Windows. It was originally designed to remove only USB pen drives but will now eject any USB device. It can be run as a non-visual command line program or a normal gui program. Its very useful if you have a USB flash/pen drive, especially if you use a menu such as PStart or the Portable Apps launcher.