2006 XP boot camp situation

i seem to have been having some really odd issues with my 2006 machine. among other things the 2006 seems no longer to be viewable on a cinema display for some odd reason - after having used a converter for many, many years - even after trying one or two other mini dp (the cinema display) to dvi converters (the 2006 mac pro). so i went out and bought a cheap used PC DVI monitor in order to view this info in this machine.

i also went ahead and got a 2012 machine which i have migrated over to. this machine has windows 7 in boot camp and windows 8 in boot camp (not sure this is working) and i expect to move to windows 10 and try and just run yosemite or el capitan and windows 10 for the near future.

however, i have a boot camp install of windows xp that i really want to continue to keep for legacy software reasons.

i tried installing xp in a boot camp on a drive on the 2012 machine but it is prompting me to register and i am not sure how to get past this.

i also have the old xp install on the 2006 machine but the machine seems to be acting up as i mentioned. also, i am not really excited about having two monitors and two computers and two keyboards on my desk (i /can/ deal with two computers).

is there anything i can try along the lines of wiring the two mac pros together so that one acts as a slave (the 2006) to the other? can i try taking the drive with xp from the 2006 machine and putting it in the 2012 machine and running xp as a native install or even as a virtual machine?

anyone have any creative ideas for this?

i am going to try and see if i can get the software that i have on the xp install put on the windows 10 install but i expect this will be a very laborious and not too fruitful effort so the idea of being able to simply boot into xp when i need to would be nice.

thanks for reading and thanks for any advice