XP extremely slow load + crash

I'm setting up a computer for my mom and obviously used standard office desktop components:

ASUS M3A MoBo (AMD 770 chipset IIRC)
2gb Kingston Memory (One stick only)
AMD Phenom Quad Black Edition
Nvidia (ASUS) some random lowend GFX
320gb SATA WD.

Sorry about bad details there, threw away most packaging already and cba yet to open up the box to find out.

Anyway, onto the problem:
Install of XP SP3 works fine.
After booting once and installing all ASUS mobo drivers such as L1 atheros NIC, chipset and realtek audio drivers, Windows XP loads INSANELY slow. The loading bar is going matrix slow-motion on me.

Checked ASUS website and updated bios from 0501 or something to 1001. Supposedely fixes a lot of problems, except for mine!

Booting XP straight doesnt work, after looking at my slowmotionbar for 10-12 minutes, I get the black screen of death. Fail-safe mode actually works, but not fail-safe mode with networking. I suspected NIC-driver issues, so burnt a CD and updated to latest. (The BIOS-option halt-on no ethernet cable seemed EXTREMELY laggy. Never noticed a laggy BIOS option before. That was before BIOS flash though)

This is my second try at installing XP; stuff not fixed in this install:

Windows Update
VGA drivers

Stuff that i tried on last install but didnt help:

Windows Update
VGA drivers

I'm beggining to suspect memory. Will run memtest after posting now.

any help appreciated.

Memtest+ so far has no errors, been running for 20 minutes.

I'll try to reset bios, but i suspect settings are auto-reset when you update. Done loads of warm boots, hdds however!

This is like the 2nd SATA device I connect, so if i've made any mistakes there it wouldn't be too suprising. I've tried booting in IDE mode, RAID and AHCI. None of it worked, but that was before BIOS update aswell. Will try again when memtest finishes.

SATA setup:

SATA1 : WD-disk
SATA2 : nil
SATA3 : DVD-burner
SATA4 : nil

Currently in IDE-mode.

Maybe try disabling onboard lan, uninstalling the driver from device manager, enabling onboard lan, & installing the latest driver?