Using VB.Net

I cannot able to delete the database file. File also not in use.

```
 File.Delete("G:\1.txt") - It is deleting the file

 File.Delete("G:\DB1.bak") - It is not deleting

```

I used below code also,

```
Kill("G:\DB1.bak") - It is also not deleting

```

What is the problem with my code.