Valve broke Windows XP compatibility for Portal 2 back in 2011. v4560 was the last version.

For Portal 2 v4560 on Windows XP you'll need to use the skidrow crack. You can also use just the client.dll and server.dll files from the skidrow crack with SmartSteamEmu.

I've never tried newer builds of Portal 2 with Windows XP w/onecoreAPI or API wrappers so that may be another option, the above is for vanilla XP. Portal 2 v4560 does work on Windows 2000 w/BWC with the crack though.

HL2 + EP1 + EP2 + Source + Lost Coast last I checked v5377866 (9/2019) was the last for XP.
Portal v1910503 (12/2014)

Not valve but for Black Mesa (not the standalone mod) 12/26/2019 was the last working ver ver. I faintly remember being able to use the bms folder from newer versions with the 12/26/2019 binaries on XP.

DosFreak wrote on 2023-12-03, 20:26:

Valve broke Windows XP compatibility for Portal 2 back in 2011. v4560 was the last version.

Ah, that's a shame. I assume it's gonna be a PITA to find, being as old as it is?
Regarding One Core API, I've tried to get it working on my machine earlier, and it just flat out didn't work, so I assume it wouldn't have any effect on Portal 2...

Interestingly, there seem to be people out there that did get the game working with newer builds, such as:

https://steamcommunity.com/app/620/discussion … 45825904129080/
"What happens to this game when Steam breaks on XP?" - Posted to Portal 2's community page in 2018

https://www.youtube.com/watch?v=IaDmhUlhkhU
"Gaming on Windows XP in 2019" - Portal 2 is one of the games featured here

DosFreak wrote on 2023-12-03, 20:26:

Not valve but for Black Mesa (not the standalone mod) 12/26/2019 was the last working ver.

This is not true, the latest Steam release (downloaded 2 weeks ago, again via SteamCMD) works just fine. The only issue is with the new UI, running the game with -oldgameui parameter is without any issues.

I don't currently have the version number available for BMS, all I have are the files I've saved for when I last tested and when I last tested that version worked and newer versions did not. Same with other HL2 engine based games due to Valve updates. So either what you've downloaded is an older version or the BMS team was able to fix what Valve broke.

Just because something is downloaded in 2023 or read in a forum in 2023 doesn't mean the files you downloaded are from 2023 or that people in that forum were using the latest version as of that time that they posted.......

DosFreak wrote on 2023-12-03, 20:48:

or the BMS team was able to fix what Valve broke.

Black Mesa was never affected by the HL2 updates, since it's source branch is entirely separate. As I said, the game only crashes when using the new UI, which can be disabled via -oldgameui

Think we have different opinions of working and not working and issues and without issues but if that switch works consistently on newer versions of BMS to get the game working on Windows XP then good to know.

For Portal 2 versions newer than v4560 you can see if you have any luck with the Goldberg Steam emulator, be sure to copy the ws2_32.dll and ws2_base.dll from OneCoreAPI into the same directory as the goldberg steam_api.dll file or you can use a fork of Goldberg for XP which is based off of an older version of Goldberg https://gitlab.com/this_isnotme/winxp-goldberg-emulator.
I use Goldberg on Portal 2 for Vista and above. Last tested with build v7293.

DosFreak wrote on 2023-12-03, 21:13:

For Portal 2 versions newer than v4560 you can see if you have any luck with the Goldberg Steam emulator, be sure to copy the ws2_32.dll and ws2_base.dll from OneCoreAPI into the same directory as the goldberg steam_api.dll file or you can use a fork of Goldberg for XP which is based off of an older version of Goldberg https://gitlab.com/this_isnotme/winxp-goldberg-emulator.
I use Goldberg on Portal 2 for Vista and above. Last tested with build v7293.

I find a thread on MSFN, that mentioned Portal 2 working on XP up until 2022, so I gave it a go. I download "previous_release" beta branch on Steam, which is a build 8151 (there is also older branch, "demo_viewer", which is build 7682), and use some crack, that I had saved in my backup files on NAS. It included LumaEmu.ini, so it must be based on that, and with it, I was able to run a play Portal 2 on my ThinkPad T430 with Windows XP.

On Windows 7 (on the same laptop), steam_api.dll from Goldberg Emu (that XP compatible one) was enough to run the game without any additional crack. Unfortunately, with the same dll, game won't work under XP.

I know this discussion is old, but I am looking for the same sort of solution. I am trying to run Portal 2 on Windows 2000 (with Black Winged Cats Kernel extension). For the sake of this, I think we can assume Windows XP compatibility. Was there any conclusively to this discussion? I also don't currently possess an official PC copy because I already have it on console and I am uncertain on getting the PC version to work, considering the number of dead old links and no longer hosted files, is the steam beta/old release branch after purchasing the only means of getting an old copy in y'alls experience? And then I have to find a compatible crack to run it without steam...

I don't have much money so I really don't want to spend it without certainty.

Any advice or pointers in the right direction for the files?

PS I have already been able to run Portal 1 on it smoothly.

According to the post above yours you can download builds newer than v4560 and they work on vanilla XP....which I doubt. (Unknown about 2000).
All of my tests were done with Vanilla XP which is why I used v4560 since builds newer than that never worked for me.

So the legal way to to acquire Portal 2 would be to purchase it on Steam, download Depotdownloader and use the info from Steamdb to download an old build (or try the newest build downloaded via Steam):
https://steamdb.info/depot/621/manifests/

Once Portal 2 is downloaded you'll then need to crack it, it's unlikely that Goldberg using OneCoreAPI (Might not be needed with BWC ) files or the fork of Goldberg will work but you can try them.
For the v4560 version of Portal 2 I used the skidrow crack for Portal 2 which has modified client.dll and server.dll files which I used together with SSE (SmartSteamEmu).

For the v6180 ver of Portal 2 on 2000 (BWC) just goldberg with the command "portal2.exe -steam" worked fine. At the time I tested that was the latest version that worked for me.

If goldberg doesn't work with BWC then bring it up with BWC (MSFN forums) to see if it can be made to work, it's either that or work on the Goldberg XP fork to get it to work assuming that it doesn't on XP.

As far as money just skip starbucks 2 or three times. Portal 2 on PC is worth it.