Need some help getting my AMD 64 + Chaintech mobo to work.

[AncientPC]

Specs:
* AMD 64 3000+ (socket 939, 90nm)
* 2GB PC3200 Kingston HyperX Dual Channel DDR
* Chaintech NVF4 nForce 4 Ultra chipset
* Sapphire Radeon X300
* 2 x 120GB WD SATA hdds
* NEC 3520A 16x DVD+/-RW



I'm getting an idle temp of 21ºC! [img]/images/graemlins/grin.gif[/img] I'm used to 60ºC - 72ºC.

I'm running into a lot of problems though.

1) My existing ATX power supply doesn't exactly fit:


2) Installing WinXP SP1 or SP2 gives me BSODs upon login. IE crashes when I go to http://windowsupdate.microsoft.com/, and I can't open up that page with Firefox. [img]/images/graemlins/mad.gif[/img]

3) I can't install WinXP 64-bit Professional, it gives me this error:


4) I can't run certain random programs like Outlook which gives me this error:


Anybody have any ideas? I'm kinda lost here. [img]/images/graemlins/frown.gif[/img]