Could also be a slow net connection if ff is slow . there are a few config things for firefox in the about
:config
About:config entries - MozillaZine Knowledge Base also for the open office there are some adjustments to speed it up.
also maybe look for a faster card. I gave my nephew my old PC he still uses it for online gaming and has no problems with it I just set up a couple of reg files that turn off not needed things ,that he clicks on before gaming ( online) and then when he is finished gaming he clicks on the reg files and reboots and everything goes back to normal. he play RTCW Enemy territory and also WOW, LOD. he has no complaints at all mind you he is using my old 17"LCD. I also built my niece and old P42.66ghz she downloads and watches allot of tv episodes . the both use XP with the drive partitioned ( Kind of like a Linux setup) with all the OS files on one partition and the programs on another. once a month I go to there places and check things to make sure that they are running smooth which they are. Chexck to see how many process's are running if he isn't doing anything intense I would think that there should be no more then 23 process's runing that is with winword and Firefox open , if there is more then 23 process's running check for Virus's and spyware and go to the Blackviper website and read through which process's he needs running and which not to run . I had my computer down to 17 process's running and that thing was faster then my Dual core when shutting down , booting up.