Function IsAccess(AFileName : String):Boolean;
const
Flag = 'Standard Jet DB';
FlagSize = Length(Flag);
var
hFile : Cardinal;
Header : String;
begin
Result := False;
hFile := FileOpen(AFileName, fmOpenRead or fmShareDenyNone);
if hFile = INVALID_HANDLE_VALUE then
Exit;
SetLength(Header, FlagSize);
FileSeek(hFile, 4, FILE_BEGIN);
FileRead(hFile, PChar(Header)^, FlagSize);
Result := Flag = Header;
FileClose(hFile);
end;