Internet Explorer alert & Firefox trouble

Hi! I am really a novice with computers. I am trying to learn as I go.
I have an Acer computer with Vista.

I have a question about Internet Explorer. I updated to IE8 and now I get a message everytime I open a new page. The message is "Do you want to allow software such as ActiveX controls and plug-ins to run?". Is there a way to stop these alerts? They are annoying!

Also, I downloaded Firefox and was using that since IE was so slow and getting the pop-ups. Last week, my computer shut down unexpectedly while I was on Facebook. Ever since then, I can't use the search bar, can't bookmark, and there is no history.

Any suggestions on how to fix these problems? I really am not very good with computers so I'm sorry if I sound naive!

Thank you,
John987

 

I solved the Internet Explorer problem by resetting the security to default.

And I just deleted Firefox.

If anyone has suggestions on Firefox, please let me know. IE is so slow!

Thanks, again!
John987