Persona 3 Reload has unusually useful public Steam Cloud metadata: SteamDB shows the exact WinAppDataRoaming root and SaveData*.sav pattern. That makes the Steam backup boundary clear, but it does not solve Microsoft Store compatibility because the Game Pass version lives in WGS and community transfer workflows use conversion/encryption-aware tools. SaveEditor therefore documents both locations while explicitly separating “where the file is” from “whether it is directly compatible.” A safe migration starts with a complete backup of both source and target directories.
Identify the exact save you intend to edit
The researched Persona 3 Reload PC save location is Windows: Steam: %APPDATA%SEGAP3RSteam<64-bit-SteamID> ; Microsoft Store: %LOCALAPPDATA%PackagesSEGAofAmericaInc.L0cb6b3aea_s751p9cej88mtSystemAppDatawgs<user-id>. Known file/folder pattern: Steam: SaveData*.sav; Microsoft Store: opaque WGS files/containers.. Storefront context: Steam, Microsoft Store. The Steam and Microsoft Store save containers are not equivalent. Do not rename an arbitrary WGS file to SaveData001.sav and assume it is valid. Do not edit a similarly named file from a different profile, edition, or cloud cache.
Make an untouched backup first
Copy the complete Steam-ID directory or the complete Microsoft WGS tree before any transfer. Keep original SaveData files untouched until the migrated save has been loaded and re-saved successfully. Keep that copy outside the live save directory and do not overwrite it with later experiments. Cloud context: Steam Cloud and Xbox Cloud are documented. SteamDB reports a 550 MiB cloud quota and the SaveData*.sav pattern for Steam. If a launcher can synchronize the save, prevent it from silently replacing either the original or edited copy while testing.
Understand the format boundary
Steam cloud configuration explicitly maps WinAppDataRoaming/SEGA/P3R/Steam/{64BitSteamID} with a SaveData*.sav pattern. Microsoft Store uses WGS and transfer to Steam may require format/encryption-aware tooling. File-extension context: .sav Compatibility note: Game Pass-to-Steam migration can require encryption/container conversion. The existence of both files on disk does not make them byte-compatible. These facts help identify the save but do not automatically reveal every field, checksum, encryption rule, or version-specific structure inside it.
Use only a Tool whose claim matches the file
Generic viewers and diff tools can inspect bytes without claiming game-specific semantics. A game-specific editor should be used only when its Tool page explicitly lists Persona 3 Reload, a matching supported version/container, and a Verified operational runtime. A planned URL or Game Hub is not evidence that an editor exists.
Test the edited copy safely
Write to a new output file when the Tool supports it, keep the original backup, restore the edited copy into the correct profile/storefront location, and launch the game only after the file operation finishes. If the game rejects it, If Steam does not show an imported slot, confirm the 64-bit Steam ID folder and SaveData numbering. For Microsoft Store migration, restore the original WGS copy if a conversion tool fails. Return to the untouched backup before trying another change.
Verification context: Reviewed against PCGamingWiki Persona 3 Reload and current SteamDB user-file-system mapping for app 2161700.