Tons of games suddenly can't be played on Windows 7

[BlackHaloRose]

So, I've been trying for the better part of a week now to help my brother figure out what's wrong with his computer. It started about 2 months ago when his League of Legends started to give him problems, crashing several times before a game started. After several fixes, he finally got it working again by simply running as admin. That worked till about a week ago and now his launcher crashes every time so he can't play the game at all now. While we're trying to fix this problem, we play some games on Steam, such as Left 4 Dead 2, which works just fine. Two days later, his Left 4 Dead won't start up and then he soon finds out none of his games will start up that are 3D. (Games like Divekick still run fine for him.) So now he can't play anything 3D.

Here's what we've tried so far that has resulted in minimal changes.
-Restarted the computer several times.
-Completely updated windows 7 with even optional updates.
-Verified game cache files.
-Updated drivers as much as possible. (This got Saints Row 4 to work again, but nothing else 3D does.)
-Tried a .blob fix for the Steam client
-Tried reinstalling League of Legends and various steam games, but problems continue to persist
-We haven't done this yet, but I doubt it's a registry issue, because he downloaded a new game I gifted him and even that didn't work.
-Tried running everything as admin.
-Have run several anti-virus and anti-malware checks on his system to find out if there is a virus affecting his system, results came back negative.
-Have tried repeatedly booting up one game in case it's a % chance of launching, have never succeeded with this.
-Restarted his router (This fix was aimed directly at his League of Legends problem.)
-Has let the computer stand in a powered down state for an hour or two.

I'm far from a computer expert, but I just can't seem to find a reason why his computer can play games one day and the next can play absolutely nothing. I've done numerous google searches for several of the games with the types of errors he's getting, but nothing seems to work or completely match up with the problems he's experiencing. It would be easier if each game was having the same problems, but they seem to be behaving differently with each problem. Left 4 Dead 2 for instance will say that it's launched, Steam will say he's playing it, but it will never finish booting up and will stay that way until he ends the process. Payday 2 will prepare to launch but then immediately close itself. League of Legends launcher won't stay open. It's just a mess of different issues.

My brother and I have identical laptops so most of the information below should hold true.

System Manufacturer   TOSHIBA
System Model   Qosmio X505
Processor   Intel(R) Core(TM) i5 CPU       M 460  @ 2.53GHz, 2534 Mhz, 2 Core(s), 4 Logical Processor(s)
Graphics Card NVIDIA GeForce GTX 460M
Operating System Windows 7 Home

Let me know if there's anything else important I'm leaving out. Any solutions to any or all problems would be greatly appreciated.

[Geek-9pm]

Toy have already done most of what can be done. 

Does this problem only show on games that have to be played on-line?
Does the problem is only for copyrighted programs that require a license?
In over words, Are you trying to get around some restrictions the software placed on your use of the programs?

Just asking. Not accusing you of anything wrong.

[BlackHaloRose]

We are not trying to get around any restrictions, no. And the problem occurs with non-online games as well.

[Geek-9pm]

Here are two ways to moving ahead.
1. Assume it is a hardware issue and start doing substitutions of hardware components. And do a long memory test.
2. Assume it is a operating system aberration  ad re- install the entire system.

That latter option is easier if you have a backup method that lets you go back to an earlier time, like six months back.

My best guess: Something happened to yurt BIOS firmware. Just a guess.

[kyle_engineer]

First of all, gj on the diag so far! 

You can also do a system restore (if you have restore points on) to before this became an issue... maybe a week to so before.

Honestly it could have been several things that caused it. Since it's affecting ALL 3D games, it's most likely RAM/CPU or VRAM/GPU oriented if it is a hardware thing. It could just be an issue with DirectX3D though... or any other part of Direct X for that matter... so software is a possibility too.

It is also possible that the newest drivers for the GPU are causing issues, and that updating them in an attempt to fix problem A (LoL not working) that it lead to problem B (no 3D rendering capability).

Personally I'd say roll-back your GPU driver to the version you had prior.
-- If that fixes 3D rendering issues, then you're 60% of the way to fixed.
-- After 3D issues are tackled LoL may work. If not, then try fully deleting everything relating to it (Revo Uninstaller works well) and installing anew.

If that gets you no where, then do a system restore to before. If that works (which I can't see it not working at least temporarily) then check all your versions and note everything down you can imagine. I say do this in case it starts erroring again you'll have comparative data.

If that doesn't work stably and you still don't get any good solutions digging online - do a clean install.
Backup all the documents you want (aside from game stuff), reformat and reinstall windows (or a factory restore depending on the disks you have).

-klye_engineer