As much as it's job security, these things waste our time.
Helpdesk is for when a system goes down, or when something technical goes wrong, as well as password resets, etc. The worse is people who screw up their computer so badly they cause some of the most bizare problems. Now the power one is easy, but I've seen some really messed up software issues take a while to fix because of the user totally screwing around.
Then you always get the people that call like twice a day to change their password because they keep forgetting it, yet they blame us "why does this keep happening?" Sometimes I'm bold and I just say it "because you forgot your password".