I would not open all emails and certainly would turn off the PREVIEW in any version of Outlook due to the PARASITE problems that can cause such ills.

Look at:

http://www.mvps.org/sramesh2k/IEFIX.htm which makes IE/OE repairs fairly automatic.

http://www.doxdesk.com/parasite/ which is a beginner's treatise on this new problem.

And could it be that you just need to resize such a window?

In closing, if you added a firewall or popup stopper, then ask for support from that product's support site. With modern browsers such as Firebird and Mozilla, popup stoppers are not required since they are builtin. The firewall for Windows 95, 98 and ME is an oddity since there is no documented exploit that shows we need such. I find that for Windows 95/98/ME that it usually just creates more support calls and doesn't save anyone.