Why can't I open a new folder on my desktop?

Sadly I am no computer whizz, but I'll try and describe the problem as clearly as possible:

When I try to create a new folder on my desktop, one of two things happens.

1: the new folder appears to be successfully created - the icon appears on the desktop - but then claims not to exist when I try to open it. These "phantom" folders also can't be deleted: again, because they "don't exist".

Or 2: no folder icon appears at all.

Exactly the same thing happens with Word documents. These non-documents deny their very existence with an error message when I try to open or delete them.

This has also happens retrospectively with folders which have been successfully created. For example, I created a folder and saved a few Word documents in it, only to later turn on my computer and be told that the folder no longer existed. The Word documents contained in it were therefore inaccessible.

Any ideas would be much appreciated!