Your power supply being at 450 watts should have in it a 40 - 50 amp rail. If not then it could fail and damage things.
Meh, it was around 44 AMP I guess.
I got another power supply now, though. The cables of the 450 watt one were too short, lol.
This time a 750 watt Antec power supply, which is modular. An Antec TP-750 to be exact.
The new case is awesome. Plenty of room, without tools

I routed my cables through the cable management system (a bit of a pain) and now the computer really is organized.
All cables are in the place they should be, so I can easily swap parts or something when I need to.
The only part where I had to use a screwdriver was to untighten the screws (Cooler Master's good at tightening them, lol) and to screw in the motherboard.
Oh, and screw the screws, they keep flipping off of my screwdriver

I also attached my PC to my medium-sized TV and to my stereo system. It's an entertainment system now, as I'd call it

I can play several games like Portal 2, Bejeweled 3 and the like. Okay, it's not the optimal gaming experience but why do you expect my dad to buy new parts?

Placed a shortcut to Windows Media Center on my desktop, so mom and dad can play video's when they want to. I'll use the traditional file-opening, lol.
Take a wireless keyboard and mouse set with that, and you've got complete couch-control here in our pavilion (is that the right word?)

Updated the first post to reflect my current specs.