When possible you always want to use Hardware flow control. However, if your modem is having a hard time negotiating an error-free (v.32bis, etc.) session, Dial-Up Networking will hang up on you and claim Msen did it. How rude!
You can disable the requirement for an error-free session by unchecking
the box here. However, if you are having problems because of this,
you may want to check the following things:
Unfortunately, some modems simply refuse to negotiate error-free connections between each other. Aside from adding some additional init-strings, there is little you can do. These init-strings can go into "Additional settings". If you suspect a noisy line, contact Ameritech.
To find out exactly why your modem is being disconnected, select "Record a log file". Try to dial and then close Dial-Up Networking. A file called "modemlog.txt" will be created in your Windows directory. This file will tell you if you are being disconnected due to lack of an error-free session.