I have an iMac 22 inch, about 2 years old.
I had the habit of saving useful stuff "to desktop", for easy retrieval.
Now I find I cannot delete any of them.
I use a password in the computer generally, and the deletion message always asks for my password, which it then fails to recognise.
I have never changed the password in any way since starting with this computer.
What have I done/am doing, wrong?