IE is embedded in Windows. I have not seen a successful method to remove it myself and still have Windows function properly. As long as you perform security updates and have firefox also up to date with its updates and have Firefox as your default browser, the only way IE could be a problem is if malware explicity calls for
IExplore "www.google.com" where google is replaced with a nasty URL using redirection to a website that can take advantage of an IE exploit, and start IE on your system and hit that nasty site which usually will take advantage of exploit and then send in a payload such as trojan horse etc. Surfing the web thru Firefox you should be pretty safe as long as you dont downoad a problem thru that that uses an IE Explicit Redirection instruction. Firefox has a pretty good antivirus built into it, but I also always double check downloads with another AV to be safe. The only issue with XP is that its coming to an end for security updates, so you might want to go with Vista, 7, or 8 or Linux to stay supported and secure.
