Does it happen when you visit a specific website or it crashes randomly?
Are you up to date on all the critical IE patches? Did you recently install
a IE plugin? is so try to uninstall it or get the latest version and see if
that helps.
You may want to default all the IE options, see if that helps. If so then
customize the config options and see if that changes the stability. Some
other things to try is to clear all the IE cookies, temp internet files and
history and windows temp folder. Also do a check for Adware using SpyBot and
Adaware, both are free utilities. Perhaps some adware installed a
BHO(browser helper object) which causes IE to crash.
If all else fails, sometimes IE needs a fresh re-install. That helps most of
the time with software.
Goodluck!