Set up a file on your desktop and call it 'Backup'. Copy all information in your folders/documents to it. In the backup folder create another folder 'favourites'...copy all the files from your favourites folder into it. make a note of your connection settings so that you can manually set them up on the new computer. Save all your email addresses as CSV files...file export-address book-CSV. You may need a couple of floppies and check the floppies, when written, to ensure that the info is not corrupted. When you get your new computer transfer all the info and ensure that it is all working and present/correct. Then all you have to do is delete any files on your old computer and empty the recycle bin.
Unless you are a spook from MI5/Mossad/CIA this will be more than sufficient. You could also reformat or use the restore disk if you have one. Do not touch the old computer until you are CERTAIN that you have copied everything over.