Boot to OS Troubles

I have an approx 8 year old homemade computer, made by a computer programer friend of mine that since moved away. It has been upgraded with hard ware a few times, video card, ram and a new hard drive, but nothing has been added or changed in at least 2 years.

It has:

An in Intel 2.4 g processor, socket 478 chipset.
Asus PS4533 Motherboard.
1.5 g ram.
256 NVIDIA video card.
Creative labs SoundBlaster Audigy Gamer sound card.
Windows XP Pro.

This computer has always worked great and I keep the drivers, which I know of, up to date. I have never updated the mother board drivers, though as I am not sure which ones to use as none of them I read about on the ASUS forum seems to fit what I have or need. Also, I have read that if you are not having bios problems then to just leave it alone.

Recently I have had troubles getting it to boot all the way up properly.
It goes all the way to my desk top screen, loads all my icons and background and than freezes and fails to go any further. I does not load my other start up programs such as wireless network, Norton, sound icons and other items that are in my lower right hand start up tray. I have to manually shut it down by holding in the power button and then restart it. It usually works fine the next restart and even many time loads properly on the very first try.

I have NO spy ware or viruses as I have Norton and Ad-aware that I run every few days and keep installed and on for constant protection.

As a note. When and once it does load properly, this system runs with out a single flaw.

Any Ideas on possible fixes would be appreciated.

 

Start with major Attitudes cleanup, if you have not done in some time.
http://forums.majorgeeks.com/showthread.php?t=106650
If you have , come back , and we will try to help more.