or alternativley if you are running xp you can click start, set program access and defaults, there are 3 choices, microsoft windows, non microsoft and custom, chose custom, on all the options buttons click use current option,( the top one of the two) and then click enable access to the programs (opposite current option button) so that a tick appears in the box, then at the bottom of the page click ok.

this should restore your settings to be able to work the manage addons options button on your ie7 toolbar then follow the instructions from my first post and it should be saved automatically every time you exit and restart the browser.