Something wrong with my computer?!?

I don't know what my little brother has been doing on my computer...but now, whenever I try to open Internet Explorer, it won't open and automatically says "Internet Explorer has encountered a problem and needs to close. We are sorry for the inconvenience." (I'm using FireFox to write this) Also, my anti-virus can't update and I've tried downloading others but they won't work for weird reasons...Avria Anti-virus tells me "Error during reading the definition file!".

My Firewall is still working and so is my spyware protection but I'm worried about IE not working and my anti-viruses! Please help :(

Something wrong with my computer?!?firewall

Try reinstalling Internet Explorer. Avira usually uses IE to download files.

Method 1: Install Internet Explorer 7

You may be able to resolve problems with Internet Explorer 6 if you install Internet Explorer 7. Installing Internet Explorer 7 probably will not resolve problems with Outlook Express.

For information about how to install Internet Explorer 7, visit the following Microsoft Web site:

http://www.microsoft.com/windows/product... (http://www.microsoft.com/windows/product...

Note After you install Internet Explorer 7, you can repair damaged files or missing registration information in Internet Explorer 7. To do this, follow these steps: