We have two computers in my house;
My computer: Pentium 4 1.6ghz which I use to play games like half life and UT2004
My mom's computer: Pentium 4 2.0ghz which she uses for internet, email, word, and publisher
My question is, if I switch the processors, will either of us notice a major difference in performance?
You wont notice any difference unless her chip is a northwoodB. Then it's quite possible that your mobo wont support it.
If bothe a northwoodA chips (100/400 fsb) they are so memory bandwidth starved that there is no real difference in performance.