Thanks for getting back regarding the version/build of Windows 10........that 1709 version, build 16299.248 is the latest as of this date. So, you're up to date with your Updates. GREAT!! That build number will change as Windows Updates itself. The Version 1709 is what they called their "Fall Creators Update" which has been a few months ago now. If Windows follows its pattern of upgrades, a newer version may not be too far off.
But lets work with the one we've got.
I'm happy to report some of the things I mentioned in my
Windows10; Large Address Aware; SH4 Install are not needed to check with this newer version 1709. For instance the older legacy NetFramework versions are now
included in the v.1709 build...and their "Enabled", so you don't have to go through your system and hand set their settings. Already done for you!
This means loading Large Address Aware onto your system to provide the game more access to the additional memory the game didn't plan on you having, will be much simpler. The question of which version of LAA should I use, is answered for you with the new 1709 build....use the "laa_2_0_4_NetFramework_4_5.zip" to work with the newer NetFramework v4.0 and newer, which is what's in v1709.
Now, your question of using a Steam download for the game.....oh boy, I'm not a Steam user. Never will be. I buy disk versions of games and never allow a seller to dictate to me when/what I can download. As you've already found out with Steam, you've had to purchase the "Base" SH4 version 1.3. To upgrade from v1.3, one of the most bug riddled game version Ubisoft pushed out on us (version 1.4 was much better!!) you've had to repurchase the last version of SH4 (v1.5) for an additional cost. Steam knows exactly what it's doing......getting players to buy a faulty version of the game, just to resell you a more stable version!! Sorry,
I don't play that game!
So, I'm going to suggest you look here
SH4 <> TUTORIALS <> HOW TO DO IT <> INFO <> DOWNLOAD LINKS -STICKY INDEX. The THEBERBSTER is a Steam user, so he's got some very good insight on what to do with a Steam download of the game. When you get your Steam questions figured out, I'll be happy to help you with anything else Windows 10 related concerning the game.
