Start up aggrivations

Hi, thanks for participating and any help you kind folks might have with a
couple little issues bugging me.

When Windows starts, sometimes my quick start menu icons don't appear on the
taskbar and I have to use the taskbar right click menu to get them back. I
don't know why but I wish I could fix it.

Also, when Windows starts, I keep getting a message box saying I am out of
disc space on my back up D: drive, prompts me to run disk clean up on D:
drive to make space, which shows to have no trash to even remove. The reason
it started doing this is a mystery to me. The D: drive shows to have pretty
much nothing on it except the Norton back up restore files. I used to back up
all my Itunes and everything to D: but started using online backup then
suddenly when empty the D: drive acts like it has no space when there's
nothing on it. The problem is that I don't know if this is a hardware or
software problem.

whacha think?