why does my pc save "ghost" versions of docs, named "~$*" etc

[rosglee]

Often when a doc or spreadsheet is open, the folder shows a faint copy of it,
with the name "~$[then the last few letters of the file name]". This doesn't
always disappear when the file is closed. It can be opened, but contains
nothing but gobbledegook.

 

[DL]

They are temp files used by whatever Office Component, they should
'dissapear' after a few moments when the file is closed