Add this to your VM XML (virt-manager) or QEMU command line:
: Since Windows XP is no longer receiving security updates , it is highly recommended to run it with "No Networking" or behind a virtual NAT that blocks external internet access. windows xp qcow2
Unlike raw images that take up their entire allocated size immediately, a QCOW2 file only consumes physical disk space as data is written to the virtual machine. For instance, a 20GB virtual drive may only take up 1-2GB on your host machine after a fresh Windows XP installation. Add this to your VM XML (virt-manager) or
use VirtIO or SATA drives during the initial install. Windows XP does not have native drivers for them and will fail to find a hard drive or throw a 0x0000007B BSOD. Stick to for the initial setup. use VirtIO or SATA drives during the initial install
Would you like detailed steps for creating a slim, optimized XP qcow2 from an ISO?