`DWORD` is defined as `int32`, so `DWORD(...)` would not work as
expected. When writing to files larger than 2GB, exception occurs:
```
unhandled exception: value out of range: 4294967295 notin -2147483648 .. 2147483647 [RangeDefect]
```
This PR is a quick fix for this.
P.S. Why `DWORD` is defined as `int32`?