I have put all the download links so you just have to click on them to download for windows xp sp2 :
openoffice for windows: http://openoffice.bouncer.osuosl.org/?product=OpenOffice.org&os=winwjre&lang=en-US&version=3.1.1
Firefox(web browser for windows): http://www.mozilla.com/products/download.html?product=firefox-3.5.3&os=win&lang=en-US
antivirus(avast home edition): http://www.avast.com/eng/download-avast-home.html
or avira free edition: http://www.free-av.com/en/download/index.html
email-Mozilla Thunderbird(if you want to replatce MS outlook or outlook express): http://www.mozillamessaging.com/thunderbird/download/?product=thunderbird-2.0.0.23&os=win&lang=en-US
Video converting(all features of ffmpeg): http://winff.googlecode.com/files/winff-1.1-setup.exe
Audio -if you dislike windows media player(supports MP3, MP4, AAC, CD Audio, WMA, Vorbis, FLAC, WavPack, WAV, AIFF, Musepack, Speex, AU, SND): http://www.foobar2000.org/download
for writing, copying cds/dvds: http://download.cnet.com/Burn4Free-CD-and-DVD/3000-2646_4-10217894.html?part=dl-6225127&subj=dl&tag=button
Making and extracting archives(zip, etc) : http://www.thefreesite.com/easyzip111.htm
Hope this is helpful enough.
That's all I can think of and have time for right now. Got to study for a math exam in school tomorrow.