pen drive question

[Joe Bollard]

hello friends, firstly, i'm not sure if this is the correct list on which to 
ask this question, if not my apologies to the moderator,  and secondly, i 
have tried unsuccessfully to solve the problem myself, i have a pen drive, 
on which there is one file i can't delete, in fact it's not actually a file, 
it's just one character, the "at"  sign, it must have been part of some 
document  i had on the pen drive at some time, it's been there for ages, and 
i want to delete it, but every time i try i get a message saying "can't 
delete this file cannot find the source disk" i want to delete it but can't, 
any suggestions, god bless, travel safely, joe bollard, the republic of 
ireland.