Large file crashes system

[dred]

My system: 10.5.4 Zeph Darwin 9.4.0
cpu: AMD Athlon 64 X2 6400+
Motherboard: MSI K9N SLI Platinum
Memory: 4 gig DDR2
Hard Drive: 3 SATA
video card: ATI X1950 pro 256 DDR3 memory


I was trying to process a video file that is 4 gigs and my system keeps crashing. It seems that when I push past the 2 gig file size I have a stability problem. Not down loading, just processing on my local system.

Thanks for any help