Games won't launch on my PC

Hey everyone... I've got a buddy dealing with some PC issues and I'm stumped. I tried helping him out but couldn't make much headway. Basically, he had a bunch of games running perfectly fine until he decided to install Ryse: Son of Rome. The game was stuttering like crazy, so he nuked it immediately. But here's the kicker: now, every time he tries to launch *any* modern game, he hits this error message.View on imgur

He still has two older titles on there—Counter-Strike 1.6 and one other classic—and those run without a hitch. It's only the newer stuff that's bricked.

Anyone have a clue how to fix this mess?

Usually, the only way through this error is just nuking the app and reinstalling it (in this case, the game).

Did he actually hack it?

Give me a break... the game is definitely pirated. He tried reinstalling one of those titles that refuses to launch, and—surprise, surprise—it's still dead in the water. It won't budge. At this rate, it looks like he’s headed for a total C-drive wipe.

Honestly, I don't think a full disk format is necessary; a quick repair should do the trick...
My guess is that while the uninstaller was running, it accidentally wiped out some crucial system .dll file or maybe even messed with some DirectX components...
He could try running SystemRestore first, and if that doesn't cut it, then move on to SystemRepair?
There are plenty of great tutorials floating around online that can walk him through it...

Did he accidentally delete DirectX?
I really hope he didn't try to manually wipe the game files instead of just hitting uninstall.
Honestly, CCleaner works wonders sometimes.
By the way, how old is my little nephew now?

I honestly have no clue what exactly he wiped or how he managed to scrub the game from the drive... but hey, it's done. I got a fresh install of Windows on Friday, so... we're back in business. Anyway, thanks to everyone for the help...