New Computer. Same Issues

[Duality]

I recently had a computer built by my friend but there are many problems that come with it.

First off, here are my specs:
AMD 3800+ Dual Core
M2N-E ASUS Motherboard
1 GB DDR2 PC5300 RAM
ASUSX1300PRO 256MB PCI-E
Western Digital SATA HD 250GB
OPTIMEX 550 Watt PSU

Generic keyboard and mouse and Dell Monitor.

My friend built most of the computer except installing the hard drive which I bought and installed myself.

I started out trying to install Windows XP many times but each time there would either be an installation error or it would just freeze. I tried and I tried until it finally worked and I thought that would be the end of the problems.

Now, various things are happening. Sometimes, I'll start my computer, and then even before it hits the loading screen, it will restart by itself and ask me to Start Windows Normally, in Safe Mode, etc and if I select any option, it will restart again and do the same thing. Something odd I've noticed though is that whenever it restarts by itself and it shows the M2N-E logo, it will show weird dots across the screen. It only happens after it restarts by itself though.

If I try to start a program with high graphics requirements, my computer will restart sometimes. Each time I restart my computer, at least 1 program won't work. Sometimes Adobe Photoshop will give me a memory error, sometimes Firefox won't start when I click it, sometimes I get conversational errors when using Windows Live Messenger.

Also, my microphone port on my front and back panel don't work, and whenever I try to plug a USB cord, a headphone core or a microphone cord into the front while my computer is running, it will restart.

At first, I thought it was a RAM problem, which by the looks of it, seemed to be the case. I got replacement RAM but I still got the exact same errors as before. Everything pointed to the RAM and I even ran MemTest86 and it gave me errors but I replaced the RAM twice now and came to no success.

Now I'm typing from my old computer which at least works and I'm stuck on the start-restart problem mentioned earlier. I really need help with this as it has been happening for a while. I have warranty on all of my products so hopefully I can be helped.

 

[sPlAtOiD]

I think the best thing to do is to remove everything from this computer and start from scratch. Just make sure to ground yourself before touching anything inside so you don't damage any parts.

 

[Duality]

Thanks, I'll attempt that. I think my problem is with more than 1 piece of hardware though.

 

[Duality]

I figured out 1 problem. The SATA Port on my motherboard was very loose. But I still have the problem with memory, where random programs or operations don't work.

 

[penfold]

Have you tested the memory to be sure it's good? Also, you might consider testing your power supply.

 

[Ethereal_Dragon]

Everything pointed to the RAM and I even ran MemTest86 and it gave me errors but I replaced the RAM twice now and came to no success.

Sounds like it could be bad DIMM sockets on the motherboard. How many DIMM sockets are there, and have you tried using only 1 stick of RAM at a time in different sockets to see if it effects the issue at all?

 

[Duality]

Sounds like it could be bad DIMM sockets on the motherboard. How many DIMM sockets are there, and have you tried using only 1 stick of RAM at a time in different sockets to see if it effects the issue at all?

I've tried 1 stick in all 4 slots and to no avail. In 1 slot, it actually gives me more errors than usual. I'm thinking it may be the motherboard as well because of the previous problems with my RAM, Microphone and headphones not working.