usual - check for malware / spyware
make sure IE / Windows are up-to-date with updates
make sure any plugins (java/flash/shockwave) are up to date
make sure your RAM is OK and you have enough
clear out cookies / temp internet / temp files
I've noticed an increase in IE crashes due to srript errors in the last couple of weeks, due to implementation of this new UK cookie rule. It looks like a lot of companies are using bolt-on routines which don't properly integrate and crash IE,. Chrome / Firefox SEEM to be more stable in this respect - at present