Do I need to upgrade the PC?

[tenohfive]

I'm currently tinkering with some video editing for the first time and using two different editors (GoPro Studio and Garmin Virb Edit) both are repeatedly crashing whilst doing fairly basic tasks - stringing together several clips (less than an hour) and cropping etc.
My PC build is fairly dated but copes fine with most tasks I throw at it, including photo editing in Lightroom etc. Is it likely to be the main reason?

Specs:

AMD Phenom II X4 955BE @ 3.6ghz
16GB RAM
GTX 570 GPU
SSD for OS and programs
HDD for media
W10.

If it's not the hardware that's likely causing the software to crash repeatedly, and ideas on what it might be?

[tenohfive]

Motherboard is a Gigabyte GA-870 UD3. Can't think what the PSU is but it's a 650W Corsair one that is probably one of the more recent components to be added IIRC.

And it's just the video editing program's that end up Not Responding - it doesn't crash the whole system.