One caution on XP: the very kernel of the OS is no longer secure. Microsoft has literally patched the kernel to the point that any further patching could cause the system to stop booting. They’re dedicating almost no support to the OS for any future development.
At least, do yourself a favor and download Ubuntu Linux. It’s incredibly user friendly and more secure than XP ever was. Plus, it’s free.
Can I run my CAD programs (which were written for windows) on Linux?