You didn't leave much info, but here's
my two cents worth to start off with.
OS version? I.E.version?
Are your machines clean of spyware and virus?
Are you able to get on the www at all,
or what exactly causes the "Not Responding" error?
If not able to get on the net with I.E.,
Get Firefox, (My personal choice, for its features and customizability)
Spybot Search and Destroy To check for, and remove spyware.
Oh yeah, did you reinstall I.E.?