Budget PC

[MathieuB]

For the CPU, I'd upgrade to the Core i5-2500. The fact that it's a quad-core processor means that it's a lot more future-proof than the Core i3-2100.
http://www.pccasegear.com/index.php?main...s_id=16403

Case: The Antec 300 is less expensive and more solid:
http://www.pccasegear.com/index.php?main...ts_id=6754

Those speakers are pretty much awful. These would be already a great improvement: http://www.pccasegear.com/index.php?main...s_id=18552

HDD and motherboard are fine choices.

Video card: No need for a dedicated video card if your mother doesn't play video games. The CPU features an integrated video processor (IGP) and the motherboard can output via VGA, DVI or HDMI.

8GB of RAM is a wise choice.

PSU: Your current selection is the lowest priced reliable option. For $14 more, you can get a more efficient (80 PLUS Bronze) and more reliable Seasonic 430W PSU: http://www.pccasegear.com/index.php?main...s_id=15958
A wise investment (higher efficiency = lower power consumption = lower electricity bill) considering how long you intend to keep the PC.

Blu-Ray drive: Fine choice, but you'll also need software to playback Blu-Ray disks on a PC. PowerDVD 11 Ultra is what I recommend: http://bit.ly/bsYj5g

Rest of the build looks good to me.