New to computer building

[tragedyinmm]

Hello, my name is Trevor i'm new to computer building and i'm building a computer for my sister i keep getting the blue screen the computer will work for a while and then it will come again randomly. i think i have all the updates i need so im not too sure what else could be wrong its an old motherboard and processor and one stick of ram the rest is newly bought.

old parts
ASUS k8s-mx mobo
amd athlon 64 2800+
512 mb stick of ram

new parts
readeon 900 128 mb agp gpu
sony 18x dvd rw burner
seagate 160 gb searial ata w/ncq 7200/8mb/sata-3g
pqi 512mb pc2100 bbr 266 mhz ram

if anyone could help me with my problem i would be truly thankful. any other imformation needed to figure it out let me know how to get it and ill post it.

 

[Matthew DeCarlo]

Check the C:\Windows\Minidump directory for .dmp files and attach them in the next post.

Test your RAM with Memtest86.

 

[tragedyinmm]

i have already tested the memory and the test came out perfect i used memtest86+

these are all the file i have in that folder.
mini010808-01
mini032308-01
mini032408-01
mini122307-02
mini031308-01
mini032308-02
mini122307-01

 

[Matthew DeCarlo]

Okay, good work, you've found them, but you'll have to attach them to your post for us to download them. Attach the following .dmp files:

mini031308-01
mini032308-01
mini032308-02
mini032408-01

 

[tragedyinmm]

there you go hopefully this works.