There's an option in the IE options on managing addons. I was seeing some problems with a toolbar used here regularly that suddenly acted up and simply ended up removing it for a different version of it.
Look at what is seen in tools>internet options>programs when clicking on the manage addons button seen there. If anything else is on like some extra crap when first seeing the Google bar installed you can take of it right there.
The best addon bar seeing an ad popup blocker found so far is not Google, Yahoo, Crawler, or others but one named Dogpile! Despite the name it's a better one for general use over others seen. InfoSpace Toolbar, Browser Companion
The one thing hated most here is always needing to uncheck the "install this or whatever" toolbar while trying to get something else running! Plus the big named ones seem to attract more adwares.