Hi:
Since you are saving the data into an Access database located in the network make sure no one has opened the database while the test is running. If the database has been left open it would cause an access denied this would cause your computer to use all your system resources and eventually lock-up the computer.This can be solve by creating a copy of he database so it can be access by multiple users.
Another reason for this to happen is if the network is down or is back mode of the anti-virus is checking the network or if big files are been downloding slowing down thew network to much.
If that is the case what you can do is get your self a 2TB hard drive install it in the test computer and save he data to it.
PS. Make sure not to send NULL values to Access it does not likes them.
When you solve your problem lets us know what was the cause and solution. Thanks.