Problems with T-bird

Hi all! I've got a problem with my system!
First of all, here's my configuration:

-Athlon T-Bird 1Ghz
-MB Qdi Kinetiz 7B
-128 Mb Ram
-HD SAmsung 20 Gb U-ATA 100
-DVD-ROM (??)
-Philips CDRW800
-Sparkle Geforce 2 MX 32MB SDR RAM
-On-Chip Audio

Well, here's my problem: often when i use the sliding bar (every program) the system freezes. I can move the mouse but everything else on my monitor is frozen!
How can it happen? I think it's the graphic card, the mainboard or the system memory? Someone told me that A7V Mb has the same problem! I've tried with many OS but it's the same. Sometimes it crashes even when it draws a menu. IE it draws an half of a toolbar and then it stops, but i can still move the mouse. And if i'm listening to music, it keeps on playing for long...
How can it happen?? Should i upgrade the BIOS?
Please help ME!!!!

Paul