Got suggestions? - Windows service locking files

[mendhak]

I've created a windows service that uses a timer and an event that fires every x minutes (where x is a variable and is configurable).

The service works quite simply: It looks at a folder, enumerates all the files in that folder and every folder beneath it. It then does some processing on them (read only processing) and once that's done, it's supposed to delete all of them.

But that doesn't happen, because the service has a lock on the files.

I know I've overlooked something simple, so what should I be doing in order to delete those files?