And what happens if you press your Windows key? That should bring up the Start menu. If it doesn't, it's not just hidden. If Medab 1's idea about the double-headed arrow works, drag your taskbar back up from the bottom of the screen and lock it by right-clicking and clicking on "Lock the Taskbar."
You might also try to open your task manager, and under File choose New Task, type in Explorer.
It sounds as if you have either a registry corruption or a profile corruption. Joshuacat's instructions to do a system restore are one solution, but it doesn't always work. You can try to create another profile and then enter it and see if the icons and taskbar are back. If they are back, it would indicate that it's your profile that's messed up.
If you're able to start Explorer from the taskbar, it might be a good time to check for malware. Antivirus scan, Spybot, Adaware.
You could also start up in Safe Mode (not command line) and see if the taskbar appears there.
Microsoft's instructions for some of this here
And finally, at Kelly's Korner
, scroll down to line 195 on the right and try the VBS script file.