Brute force attack on a hashed password

Hi, I'm trying to use a brute force attack to get the password of a hased password in my app. the sql server is local. i have removed restrictions on maxinvalid attempts and have increased the timeout to a large value. The problem is that say an hour into the process IE gives a "Page cannot be found error" (the type you get when the internet is not working) and doesn't complete the process.  The password length is 10. What could be the matter? Any help would be appreciated.

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