Need major help

I am having problems getting my home built computer to perform properly. For some reason my system is bogging down with little to know processes running. I will run one program like winrar and my system will bog down and show 100% usage. I have included all my system components and operating system. Any suggestions and help would be greatly appreciated.

CPU Specs

• AOC Evercool / Socket 754/939/940 / Aluminum / CPU Cooling Fan
• ABIT KN8 NVIDIA Socket 939 ATX Motherboard / Audio / PCI Express / Gigabit LAN / S/PDIF / USB 2.0 / Serial ATA / RAID
• AMD Athlon 64 4000 SanDiego Core Socket 939 CPU
• Ultra 256MB PC3200 DDR 400MHz Memory
• Windows XP Pro
• Seagate 250GB Serial ATA w/NCQ 7200/8MB/SATA-3G
• Seagate 400GB EIDE HD 7200/8MB/ATA-100
• Diablo / 550-Watt / ATX / Dual 80mm LED Fan / SATA-Ready / 20-Pin / Power Supply


if anyone can help it would be greatly appreciated

 

type msconfig on run, uncheck unecessary programs at start up

 

also might wana check for malware/spyware/viruses
theres tons of good free scaners that you can get

 

http://www.xtreme-source.com/tutorials-pc-personal-computer/
here are some other things that may help you speed up you system.

 

thanks very much for all the help. i have tweaked the hell out of windows.. and they are brand new hard drives..i just dont know where else to look i even have tried abit as well as others...

 

am i reading that right you have 256mb memory? thats a problem right there...invest in some ram.

 

Yes 1GB of dual channel ram atleast.

256MB is just killing your system big time/

 

i meant to say 512 mb of ram my fault

 

Still killing you

 

also opening winrar in ALL pc's uses 100% the cpu

 

Well, is it at 100% the whole time you use it? Because if it's only when it starts it's normal.

But I still say to get a dual channel 1GB kit of memory for that thing or you aren't getting the most out of that wickedly fast 4000+.

 

Aside from the memory any other recommendations for the system?

 

If you wanna game I'd find out what card slot you have and get a video card... other than that... no.