octogenarian,
You have not provided your Windows version or your Internet Explorer version.
I am assuming Internet Explorer.
If you have less than Internet Explorer 7 - I would recommend downloading that.
If you have 7. You may try resetting your security settings.
Tools > Internet Optoions > Security Tab -
Click - Default leve, or Reset All Zones to default level - or if you have added some custom settings you may try choosing - Custom - then where it says reset to and by default it would be - medium high - (unless you have changed it) hit reset. - Try medium high if yours is on high.
After closing and opening Internet Explorer - if pop ups do not work then -
You may try - Clicking on the Advanced tab - then choosing -
Reset Advanced settings, if after restarting Internet Explorer - that does not work.
You may try - disabling add ons - several at a time - until - hopefully your pop ups work.
A shortcut to that is also to hit the "Reset" on the Advanced tab - it states there that it will
disable Add ons - google toolbar, yahoo toolbar, and other BHO's.
You can always go back in and re-enable them by going to: Programs > Managing Add Ons - and choosing them - one at a time - and choosing to enable them.
If you are using Internet Explorer 8 - best of luck - I am not using that.
Also if you have no luck you can try a different browser - download locations listed below:
FireFox:
http://www.mozilla.com/en-US/
or Google's Chrome:
http://www.google.com/chrome
Best of Luck