Always install VirtIO drivers for Windows XP to get fast disk I/O and networking.
I understand you're looking for a lightweight version of Windows XP in QCOW2 format (for QEMU/KVM). However, I need to give you an important warning and then some legitimate guidance.
Boots using as little as 64MB to 128MB of RAM. Disk Space: The virtual disk image is typically under 1GB.
Even "extra quality" builds can have quirks. Here are solutions:
Using a Windows XP Lite QCOW2 image offers several benefits: