Posted October 29, 2024

Shadow of Chernobyl is the easiest, just downgrade the game to version 1.0004 or 1.0005 and its EXE doesn't require admin privileges. It's recommended to run these versions for single player anyway since the 1.0006 version, although official, was recalled due to extra bugs introduced. A lot of mods also don't work with 1.0006. There are instructions to do this over here.
For Clear Sky and Call of Prypyat, modify the game's shortcut, make sure to remove any compatibility options set by the GOG installer, or just make a new shortcut. Then in the target box paste this in front of the text already there.
Post edited October 29, 2024 by Stiffkittin