What do you mean "partially hidden"? You sure can hide it, but the option "Do not show hidden files and folders" must be enabled. You also can try to delete it doing the following:
1. Try to close all the programs that may be using it (reboot your PC and don't start any programs. Go directly to the file and delete it. Kill all non-system processes).
2. Check youк HDD for errors (chkdsk /f).
3. Also check you system for viruses and spyware.
4. Get a copy of
MoveOnBoot. It's free and this simple tool allows you to Move, Copy or Delete files before Windows can lock or alter the files.