I play a steam game on my laptop which receives fairly frequent updates.It takes up to 2 hrs for an update, which I don't normally have time for on weekdays. So when an update drops during the workweek, I want to sidestep it, i.e. continue playing without updating, if possible.

The update process has two phases. The first (and shorter) phase is on the steam client side. After that, I open the game itself, and carry out the second (and longer) phase: downloading & installing the update from the title screen.

What I've learned from experience is this: Phase 1 can normally be sidestepped. Normally, when I try to open the game from steam client, there's a window for a few seconds saying the game is being launched. But after an update has dropped, it instead says Downloading Update, which if I click the only button, sends me to the steam download page. However, if I exit and reopen steam, within a few tries, it skips the 'Downloading Update' and launches the game. From there, one of two things may happen. Either:
- I get a notice that an update is available & a choice to either play the game without updating, or go back to the steam to get the update. Or
- I get a notice that the update is required, i.e. I absolutely will not be allowed to play the game without updating.

But this week, my usual strategy for sidestepping the steam side update failed. I tried exiting and restarting steam lots of times, but it never let me launch the game. Every time I tried, I got the window saying Downloading Update. So I never got to launch the game & see if it will give me the choice to play without updating.

I didn't have enough time during the workweek to actually carry out the update, but I did have enough to chase this a little further. I thought maybe if I deleted what had been downloaded (there's no confirmation button to start the download, so a little bit always gets downloaded before I exit steam), maybe steam would regard this as a fresh download, and then my exit-and-restart trick could work within a few more tries. I tried a Google search for how to remove partially downloaded updates, and found this: steamhost.cn/steamcommunity_com/discussions/forum/1/3722818939704771259
I tried to follow the instructions from the post by Supafly. I found the game ID, then went to C:\Program Files (x86)\Steam\steamapps\downloading and deleted the folder with that ID. But I got stuck on Supafly's next step: Editing the game's appmanifest. I went to C:\Program Files (x86)\Steam\steamapps\common\(game name)\manifests. There's only one subfolder: bundled. Then there's four subfolders: windows, windows-ap, windows-eu, windows-us. I have no idea which of the 4 it's supposed to be in. Tried opening one of them... Saw a file named bundled.manifest, and files named phase.manifest.1, phase.manifest.2 ... phase.manifest.16. bundled.manifest has by far the largest file size, so I tried opening that using Notepad. Searching for the string 'StateFlags' turned up nothing. Tried opening phase.manifest.1. That was much smaller; saw right away that there was no 'StateFlags'.

Anyway, the immediate issue is moot. It's now Saturday; I will take care of the current update this weekend. But it may be helpful to know how to do this for the future. Sidestepping the steam-side update, so I can launch the game, so I have a chance to play without updating, has saved me from being locked out till the weekend quite a few times in the past.