[VeedeeBee]

I've been having trouble getting my XP SP2 (to latest update KB896344) machine to start first time over the past week. At first boot up, the VGA post followed by the HDD and RAM posts come up, then blank, then re-starts, then maybe the Windows start screen (Logo and running blue bar), then maybe a start to the Explorer window, maybe the diskcheck,( it then repairs what I think are errors caused by the crashes). Most times a MS error report is posted and the response for a few days was the HP memories Disk driver was at fault, but since this was updated, I get the same thing but the MS error report is for an unknown driver. There are no yellow tabs on the System Hardware Device Manager screens that I can see so it might be a software driver.

Incidentally, once the machine is up and running, I can softboot to my hearts content and the machine works properly.

The problem seems to be very early in the boot up (as I said, between the VGA post and just after the HDD and RAM). I've not installed any new HW but with XP auto update, Webroot Window washer, Ad-Aware, AVG, MS AntiSpyware, Spybot, Zone Alarm can't vouch for software ones. Incidentally, I've made no hardware changes except to swap a faulty PCI fan (after the start of the errors).

Any suggestions (short of a complete re-build) the hardware facts are as follows:

MSI K7N 420 NForce wi on-board VGA/sound disabled (BIOS 2.00) XP 1700
XPV Geforce 128 Mb FX5700LE (set at 4x AGP max for board) up to date NVidia drivers
1x40 and 1x 120 GB IBM/Hitachi Deskstar HDD (each paired with Optical I/O device on IDE 0 and IDE 1 connections)
40 x 40 x 4 Teac CDRW (paired with the 160GB data)
Sony 16x DVD-ROM (paired with 40GB WinOS drive)
Inno USB 2.0 PCI card (have problems with this and iTunes and other player connections but more later I think this is a genec VIA vs XP SP2 driver issue)
Audigy (first version) PCI sound card
Cheapo Generic modem (HAM type - not connected)
RAM are 2 x 256 PC2100 ram

Any ideas, short of leaving the machine on 24/7?

Please forgive late responses or time to get to try your suggestions as a having to entertain a 6 year old precludes much dismantling and tweaking during the week. Thanks in advance.