|Consider using event viewer just after freeze if you can.|
Might try the latest IE 8. Could consider another browser like FF or Opera to try.
You may have to use system restore to time when it did work.
May even have to re-install the OS from recovery disk. LAST choice.
"Best Practices", Event viewer, host file, perfmon, antivirus, anti-spyware, Live CD's, backups, are in my top 10