For IE, go to Tools | Pop-up Blocker | Pop-up Blocker Settings and type the following into the Address of Website to Allow box:
*.westlaw.com
then click on Add and then add the three URLs listed below, click on Close and you should be good to go.
print.westlaw.com
next.westlaw.com
web2.westlaw.com
*Actually this works with any sort of pop-up blocker issue, but we needed to use it for our public access Westlaw computers.