I am not good with computers at all, I would be very thankful if anyone could help me.. im so frustrated!

Here is my problem!
I HAD WINDOWS 95, THEN UPGRADED TO WINDOWS XP COMP. RAN VERY SLOW SO I TOOK IT OFF. MY COMPUTER THEN START SAYING THAT THE UNICODE VERSION ATL.DLL COULD NOT RUN ON WINDOWS 95...PLEASE INSTALL CORRECT VERSION, SO I UPGRADED TO WINDOWS 98 AND IT STILL HAS THAT MESSEGE AND IT NOW ALSO SAYS THAT THE LIBRARY FILE UNICOW.DLL WAS NOT FOUND......I HAVE DEFRAGED THE SYSTEM, DOWNLOADED .DLL FIXERS NOTHING IS HELPING ME! THESE MESSAGES POP UP ALL THE TIME, WHEN IM ON THE INTERNET AND IT POPS UP THE COMPUTER FREEZES PLEASE HELP!!!!!!!!!
THANK YOU SO MUCH
CVM526
