Take the license
Take the license
I don't really like g2a, it seems suspicious. The cost isn't the issue—it's just that it would feel like a loss if I didn't have that license, especially since I won't be using that computer again, you know...
It supports your product code during installation on the new PC, which should disable the other system. What operating system version is it? EDIT: The licenses linked to the motherboard are for "OEM" versions. Did your earlier machine already have Windows installed? If so, you won't be able to use this one.
There are two main categories of OEM. One is branded, which includes prebuilt systems from major companies such as Dell, HP, and Fujitsu. The other is non-branded OEM, sold to smaller businesses that create systems for home and office users. These are also offered to hobbyists since OEM functions the same as retail but with limited official support from Microsoft and certain reinstallation restrictions.