Computer crashes when exiting Outlook…

I have a client who, upon exiting Outlook Express, will attempt to disconnect from the internet, and his system hangs. No Ctrl-Alt-Del, no mouse, no nothing. At first we thought it was simply when he exited Outlook and then we realized it was auto-disconnecting. He is running Windows 95 on a Pentium 166 with 32 MB and a mostly empty 20GB Hard Drive. I have already removed dial up networking and then reinstalled it to no avail. Suggestions would be greatly appreciated. Thank You.