Need smart computer people!!

I had to uninstall The Sims game and then reinstall it in my windows xp home edition computer, but when i went to reinstall it this error came up saying "The Win16 Subsystem was unable to enter Protected Mode, DOSX.EXE must be in your AUTOEXEC.NT and present in your PATH." I dont know why this happens, the game use to work fine w/ no problems. I searched the web for this and i found some resolutions but im very computer Illiterate so i have no idea what to do. Can someone tell me "in english" how to fix this problem? Thank you

either that file is missing from your autoexec or your path is broken. add the file and/or fix the path.

Originally Posted by redwench

either that file is missing from your autoexec or your path is broken. add the file and/or fix the path.

how do i add the file? its missing somewhere cause i cant find it on my computer