Good day fellow citizens,

since it would take me quite a bit of time, when trying to get all the newest must have mods for HL2 installed, I figured there's maybe other users, facing the same problem. This guide merely tries to save you guys some time. No need to credit or praise it. It took less than 5 minutes to write it. Let's go:

1. cleanse every trace of whatever amount of HL2 content you have installed thoroughly, google on how to do it. Simply deinstalling from Steam certainly doesn't do the trick. I recommend this, because I wasn't having any HL2 games installed, before I started going back to be playing it a week ago. This is very important, trust me!
2. Now restart your PC, and thoroughly search for any left over traces, and cleanse them. If no traces, you're good to go. If traces, then restart your PC once more.
3. Now restart Steam. Yes, do it right now!
4. In the following order install and start at least once: HL2, HL2 Episode 1, HL2 Episode 2, HL2: Update, Source SDK 2013(singleplayer)...Lost Coast and other stuff is purely optional. I figure I don't play it, so no need to install. But you can if you want.
5. If it's done to your satisfaction, restart Steam. Yes, do it!
6. I will not go into detail about where and how to download/install Mmod(MoDB 1.3 version), HD Textures(ModDB the one with rating 10.0...NOT THE ONE WITH RATING 4.7!!!), and Reshade(Google will help you). Read the instructions comming with them thoroughly. And with thoroughly I mean exactly that! Really make sure to read it all, to increase your horizon of comprehension. Done? Good! Now you should have 9 new entries in your Steam library mod section.
7. remove all leftover shortcuts to no Mmod versions of the game from your desktop, and only use the ones from Mmod. If there are no, use Steam library to make them. Make sure you create shortcuts to the HL2: Update versions(those labeled with a big U), NOT the original game!
8. start the games you want to play through those new desktop shortcuts
9. Now restart Steam! Yes, do it again!
10. now you can play

FAQ:

Do you have references of how your game looks?

Yes, browse my screenshot content.

Where exactly do the Mmod files go?

Into the steamapps\sourcemods folder.

Can other Mods exist besides Mmod in the sourcemods folder?

Yes they can. Just make sure they have their individual folder, and not in any way touch Mmod folders.

Can other SDK's exist besides 2013?

Yes they can. Specific mods will choose on their own.

Where do texture files go?

Into a \custom folder within the specific Mmod game version folder. So for me right now it is: HL2MMod_HL2U\custom

Where does the Reshade installation go?

Since you must choose a game to install from the Rshade.exe, and Mmod does not have any .exe, you would install Reshade to the specific original game. For me right now this would be the: steamapps\common\Half-Life 2 Update folder. Your presets can be placed pretty much anywhere you want, since you can select them in Reshade itself.

Did you encounter any bugs?

Yes, there is a single bug related to how the flashlight was rendered. It is in fact a SDK related bug, and does NOT come with any of the mods, or Reshade. I think it is also Nvidia specific, but I'm not sure. It happened for me on a RTX 3070. To fix it you would either use the console to turn off/on DX version 95(mat_dxlevel 90/mat_dxlevel 95), OR you would need to entirely turn of any antialiasing shipped with the game, inside the video options menu. The first solution needs to be redone every time you restart the game. The second makes it so, that wall lines do not get any antialiasing, while the rest of all the probs do. I would try to use all various AA variants shipped with the Nvidia App, and Rshade, but nothing turned out to be working.