A. Go to Accessories, and select System Tools. If you see an Activate icon, you haven't activated the OS. Alternatively, you can review the System Summary branch of System Information by running msinfo32.exe from the command prompt; if you don't see any information about activation status, then you've activated your system.
You can also use Win Info (version 2.4 or higher) from http://www.savilltech.com/wininfo.html to obtain the status of local and remote machines. Win Info tells you whether you've activated XP, and if you haven't, how much time is left before you must activate the system.