Windows Vista Ultimate BSOD Help?

Everytime I try to install a new OS on my hard drive I get a BSOD with the error:
0x00000050 (0x0BFBEF000, 0x00000001, 0x8058762A, 0x00000002)

At first I thought it was because my hard drive was corrupt or something so I bought another hard drive but I continue to get the same error.
I've tried installing a new OS on both drives but both have the same error.
Usually the error occurs right after I accept the terms of agreement on the installation of the new OS.
I've also tried running Avira but I don't think it's a virus.
I've been having this problem for a while now and It's gotten to the point where I need to flush my system and this isn't allowing me to.
Any help is appreciated.

System Specs:
Operating System: Windows Vista™ Ultimate (6.0, Build 6001) Service Pack 1 (6001.vistasp1_gdr.080917-1612)
Language: English (Regional Setting: English)
System Manufacturer: Dell Inc.
System Model: Dell XPS710
BIOS: Phoenix ROM BIOS PLUS Version 1.10 1.3.3
Processor: Intel(R) Core(TM)2 CPU 6300 @ 1.86GHz (2 CPUs), ~1.9GHz
Memory: 2044MB RAM
Page File: 938MB used, 3389MB available
Windows Dir: C:\Windows
DirectX Version: DirectX 10

hi SkeletoR1337

You need to test your RAM. Download Memtest onto a CD from www.memtest.org ... let it run overnight ... you're looking for a minimum of 7 passes on each stick ....

Spyder_1386

Alright, I'll give it a shot and post my results when I get the chance.

After running the memtest I got 9 passes on the stick.
Any suggestions on what I should do next? :/