Cannot access secure sights in IE

Hi,
My client was able to go to her banking and other secure sites. Now she can not. When you go to the banking site in IE and click log in it goes to a screen and says the page cannot be displayed. Then when you close it about:blank appears in the taskbar.In Netscape doing the same thing it pops a window saying PSM has performed and illegal. operation and will be shut down.I looked at active x controls and all seemed ok. I reset web settings in IE from the tools menu.I did a W98SE reinstall from the cabs on the HP pc. Nothing worked.