For Half-Life 2 then yes the switch works, at least the last time I tested it did:

hl2.exe -game xxx
Where xxx=game

Use the -window switch if encounter an issue on first loading the game.

I know they broke Portal 2 on XP awhile back so you needed to use build v4560. Build 6180 might work on XP with the Goldberg XP fork, haven't tested it. It does work on 2000 w/BWC
Haven't heard anything about HL2 being broken on XP (except of course for Steam), last time I tested it worked.

For HL1 you can use SSE or Goldberg (Use XP fork if using XP)

hl.exe -steam -game xxx
Where xxx=game

buckeye wrote on 2021-09-29, 21:13:

I know this has been asked "ad nauseum" but just need to know if I download the latest versions from steam and add the switches […]
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I know this has been asked "ad nauseum" but just need to know if I download the latest versions from steam and add the
switches mentioned elsewhere to the executables would I be able to play offline?

This will be for win10 not xp. Don't have fast internet at home so will have to lug my system to work and download from there.

Looked on ebay at all the discs being sold used and really don't want to go down that "mine field".

i remember playing hl2 without steam many years ago I think it was reloaded that got it to work by emulating the steam API protocols, though you should stick to the xbox version on xsx

Thanks DosFreak for the info! It's too bad you can't just buy the CD or DVD and simply play the game.

Regarding console versions, can you just play straight up on the xbox 360 or do you have to login on that too?

I own the game on Steam but I have a cd from 2005 which I always wanted to try on windows 98. Does this trick work with all versions ?

The files on the cd are likely encrypted. You'll need to either find a torrent of the unencrypted files, unpack and use a steam emulator (since older versions required steam) or download a version that already includes a steam emulator, likely the ancient steamemu.

When googling "archive.org half-life 2" you will fins an offline version.

Thanks ! I'll give it a try