The manual way to do it would be to copy your old presets to the new folders... in windows 7 presets are stored
under C:/users/(your username)/appdata/roaming/adobe/lightroom/
appdata is a hidden folder so you will have to go to open a file browser window, click organize (upper left) >folder options>view > show hidden files, folders, and drives
I don't know where the presets would have been stored on your old install, but try searching for the folder "export presets" I know that if you upgrade to windows 7 it should put all your old files into a folder on your main drive.
Hope that gets you on your way.