Use a USB drive. A 16gb one is $10
http://www.amazon.com/s?rh=n%3A3151491%2Cp_n_size_browse-bin%3A1259715011
I have 2 of these (overkill but I use them for my family photos and videos and movie jukebox for the tv:
WD My Passport Ultra 2TB Portable External USB 3.0 Hard Drive with Auto Backup - Black
http://www.amazon.com/Passport-Ultra-Portable-External-Backup/dp/B00EAS8M0S/ref=lp_3151491_1_4?s=pc&ie=UTF8&qid=1405274539&sr=1-4
To move all your files you go to on your old XP pc.
c:\documents & settings then your folder. Your files are in the Desktop, My Documents and Favorites folders.
In Windows 7 it is c:\users folder then your folder. Your files are in the Desktop, Libraries> My Documents etc. and Favorites folders.
Thunderbird email backup
http://kb.mozillazine.org/Profile_folder_-_Thunderbird
Find Firefox profile to backup the bookmarks and settings.
https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data
Firefox> Bookmarks> Show all bookmarks.
A seperate window opens. Click on Import and Backup
Click on Backup and also do the Export Bookmarks from HTML
(you will have 2 backups in case anything goes wrong)
IE: File> Import and export
Chrome: Bookmarks. (that button in upper right with 3 lines)
Select Bookmark manager.
Click the Organize menu in the manager.
Select Export bookmarks.
Just bought one about an hour ago at Office Depot for $8.99. Keep several around the house.