I had a similar problem some years ago, which were caused by Windows' automatic update, needless to say I turned it off!

>Hi,
>
>Some of our customers are experiencing something quite strange.
>They are using our app (local exe's) which uses databases on a central server 2003.
>
>Starting from a certain hour in the early evening (some 18u, others a bit later) they start getting Error reading file-errors.
>
>We already checked if there's any backup-program starting or something else, but no, not a thing.
>
>Does anyone have an idea what could be causing this? Maybe some obscure setting in Server 2003 ?
>
>Thanks for any hints.
>
>Guillaume