CaptiveX programs are in the C:\WINDOWS\Downloaded Program Files
folder. You could delete everything in that folder. Whatever is necessary can/will be redownloaded. (I just tried it)
Does the machine lock up, or just the net connection?
Can you reset the net connection - like if your net is frozen, open up a command window and do an "ipconfig /release" and then a "ipconfig /renew" and then type "ping www.yahoo.com" to see what that says.
I'm curious if it is totally dead or just kicking out for some reason.