Help me upgrade my OLD computer!

Hey guys,

Want to ask for help in choosing some components for building a new computer. My computer has been acting up a lot.

Here's my current old computer specs:
*---------------------------------------*
ABIT KX7-333 Motherboard
AMD Athlon XP 2100+ 1.73 GHz
2GB of RAM
Radeon 8500 Video Card
Creative Audigy 2 Platinum eX
Sony DVD RW DRU-500A
*---------------------------------------*

APPROXIMATE PURCHASE DATE: Nov/Dec 2010

BUDGET RANGE: $400 max

SYSTEM USAGE FROM MOST TO LEAST IMPORTANT: video encoding, surfing internet, watching movies, gaming

PARTS NOT REQUIRED: monitor, speakers, OS, keyboard, mouse, *maybe DVD Burner unless the Dual Layer burner is worth the upgrade*

PREFERRED WEBSITE(S) FOR PARTS: Newegg.com

COUNTRY OF ORIGIN: USA

PARTS PREFERENCES: It'd be great if the motherboard could come with integrated audio

OVERCLOCKING: No

SLI OR CROSSFIRE: Maybe

MONITOR RESOLUTION: 1680x1050

ADDITIONAL COMMENTS: a quiet PC will be great since my current one sounds like a truck whenever i turned it on


Any help/suggestions will be greatly appreciated!