My computer's messed up.?

What i mean is: i recently downloaded the popular game "downloader" steam, from the game developer Valve. after 2 hours of finding something to download, downloading the demo, and realizing my computer didnt have the right qualifications for it i deleted the demo and steam itself. i was told i would have to restart my computer after the removal so i did. after rebooting the computer and putting in my password, the desktop loaded up. well it should have loaded up. instead, it just showed the wallpaper without ANY icons or the start menu/bar at the bottom. after 3 or 4 seconds a window appeared which showed all of my folders and other things that i would be able to access through my icons. on the desktop clicking does nothing, left or right. i have looked through every option i can think of. i plan i taking it to best buy to get it checked out soon. i figured id try the community before i spent my money. any suggestions would be nice.