Add-ons are programs that attach to Internet Explorer to add functionality - for example, if you go to CNN or YouTube and want to watch a video  you need the Flash Player add-on.   Another common one is Java for things like animation, games, and interactive forms.    Some online game sites also require you to install add-ons to play their games.

The bar popping up is an Internet Explorer security feature so you have control over what add-ons you get..   Most add-ons are safe, some are questionable (for example, they might track your browsing history or add advertising),  a few might be malicious.

Judging whether the particular add-on you're being asked to install is safe or not is a combination of common sense and a bit of research.  If you post exactly what add-on and what site I'll try and help you determine if you need it or not.

BTW - it's a good idea to post your PC model, operating system (XP or VIsta), and any recent changes in all your posts.  If you just reinstalled the operating system from scratch, for example, you won't have the add-ons you used to have.

I understand now. There are no particular ones.

I have a dell Dimension 4600 and an inspiron 5150 and both have win xp sp3.

I am getting your full message in Hotmail account notification and here in the forum; that is fine if that is how it should be.

I hope to utilize the forum properly.

I have another post re: drivers as I am inthe process of reinstalling again as i had no sound.

Sorry if i'm a bit frazzled and thank you.