das steht in der delphi2006 hilfe:
Zitat:
In Delphi code, Reset opens the existing external file with the name assigned to F using the mode specified by the global FileMode variable. An error results if no existing external file of the given name exists or if the file can't be opened with the current file mode. If F is already open, it is first closed and then reopened. The current file position is set to the beginning of the file.
Warning:
The default value of FileMode is 2 (Read/Write
access). If this is not changed to a read-only file mode before calling Reset, attempts to open read-only files will fail.
Du musst also noch die globale Variable "filemode" entsprechend anpassen.