|If you have your system like you want it and you buy a new computer. You could transfer all that with ntbackup to the new system legally. You first install xp in the new system and apply the restore. Use system state to save some settings.|
The assumes that you have a legal retail install and not an OEM install. OEM install's will fail.
"Best Practices", Event viewer, host file, perfmon, antivirus, anti-spyware, Live CD's, backups, are in my top 10