I have acquired (don't know how) a number of tmp files in the C:/windows/temp folder. Most of these take the form CAVn (n= any hexadecimal number 1 to F), though there are also REG and Perflib_Perfdata files too. CCleaner cannot clean out these files, and manual deletion is also impossible, as this generates an error message that the file is in use. Can anyone suggest how these files might be cleaned out? They don't take up a great deal of memory, but they are an irritation. Thanks for any suggestions.