I tried SSE but when I drag the hl2.exe to the SSE Launcher windows it says steam_api.dll not original/not present

I do have a file of that name in the bin folder which came from the disks so one would kinda assume it is original and it is present

It looks like you used "Source 2007 binaries" instead of "Base Source Engine 2"

If you want Half-Life 2 + EP1 you need:

half-life 2 content
half-life 2 game dialog
base source engine 2
source materials
source models
source sounds
episode 1 shared
half-life 2 episode one

Half-Life 2 + EP1
hl2.exe 104kb

bin
episodic
hl2
platform
reslists

Place steam.dll (revemu) in the same folder as hl2.exe

You may be able SSE with these older HL2 builds but SSE is only for Windows X+ ( or 2000 BWC without the GUI except if you use blackwingcat .NET) and above compatible.
it's easier to just drop the revemu steam.dll in the HL2 folder than bother with SSE.
It's not necessary to use any steam emulator after v5135

Cheers Dosfreak. I just unpacked very one of the GCF files one after the other, so there were a lot that said source 2007 binaries.

I will list all the GCF I see on the list from sc anning disk1 sim and disk 2 sim - then if you know which ones to unpack I can start again

It is HL2 Episode 2 I wanted to install from(The Orange Box I already have HL2 Episode 1 on another second hand physical disk and steam let me redeem the key for that one and let me install it too. It is working.

This is my Windows 10 64 bit OS PC, not my XP rig

These are the contents I find when I scan disk1 sim and disk2 sim.

The gcf file names are identical on both disks but when I unpack them and combine into one folder there are some differences in the files they contain

Disk1.sim
Source Engine.gcf
Source Materials.gcf
Source Models.gcf
Source Sounds.gcf
Base Source Engine 2.gcf
Episode 1 Shared.gcf
Source 2007 Binaries.gcf
Half-Life 2 Content.gcf
Source 2007 Shared Materials.gcf
Source 2007 Shared Models.gcf
Source 2007 Shared Sounds.gcf
Episodic 2007 Shared.gcf
Half-Life 2 Episode One.gcf
Portal Content.gcf
Portal English.gcf
Episode Two Content.gcf
Episode Two Materials.gcf
Episode Two Maps.gcf
Half-Life 2 Episode Two English.gcf
Team Fortress 2 Content.gcf
Team Fortress 2 Materials.gcf
Team Fortress 2 Client Content.gcf

Disk2 Sim
Source Engine.gcf
Source Materials.gcf
Source Models.gcf
Source Sounds.gcf
Base Source Engine 2.gcf
Episode 1 Shared.gcf
Source 2007 Binaries.gcf
Half-Life 2 Content.gcf
Source 2007 Shared Materials.gcf
Source 2007 Shared Models.gcf
Source 2007 Shared Sounds.gcf
Source 2007 Shared.gcf
Half-Life 2 Episode One.gcf
Portal Content.gcf
Portal English.gcf
Episode Two Content.gcf
Episode Two Materials.gcf
Episode Two Maps.gcf
Half-Life 2 Episode Two English.gcf
Team Fortress 2 Content.gcf
Team Fortress 2 Materials.gcf
Team Fortress 2 Client Content.gcf

I thought I was supposed to unpack all in turn but that did not work so I can delete and try again, which ones should I unpack and which should I ignore, to play Half Life 2 Ep 2? I don't have 'half-life 2 game dialog' and do I use the files from disk 1 or disk 2?

Thanks

You can't play Half-Life 2 Episode 2 on the Orange Box straight from the disc since HL2 EP2, Portal and TF2 are broken on the disc.

On the detonation release which is older "half-life 2 game dialog" does exist but on the Orange Box this is included in "base source engine 2" (it's also included in the other gcfs) so ignore it.

When I extracted I likely combined the folders from each into one since I have one unified folder with 22 folders and everything works except for the three games that are broken.

I recently got a copy of The Orange Box for dirt cheap to see if there was any way to make this work without Steam (at least for Half-Life 2) which pointed me to here. The posts here have gotten me on the right track and using Phoenix to unpack the SID files came in very handy. I made a simple destination folder for the HL2 files and downloaded RevEmu version 18_02_2022. The Steam.dll I put in the HL2 folder from RevEmu that got the game to launch was in the server folder of that zip, no sign of a garysmod subfolder. Just when I thought I got the game working I get repeated crashes on the loading screens! I used Phoenix to bypass the initial startup loading crashing which variously attributes the fault modules as datacache.dll, tier0.dll, or client.dll but I also get crashes loading chapter 1 and attributes the same dll's. Such is life.